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1.
Biochem Cell Biol ; 102(3): 238-251, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38408323

RESUMO

Insects are the largest group of animals when it comes to the number and diversity of species. Yet, with the exception of Drosophila, no information is currently available on the primary structure of their sperm nuclear basic proteins (SNBPs). This paper represents the first attempt in this regard and provides information about six species of Neoptera: Poecillimon thessalicus, Graptosaltria nigrofuscata, Apis mellifera, Nasonia vitripennis, Parachauliodes continentalis, and Tribolium castaneum. The SNBPs of these species were characterized by acetic acid urea gel electrophoresis (AU-PAGE) and high-performance liquid chromatography fractionated. Protein sequencing was obtained using a combination of mass spectrometry sequencing, Edman N-terminal degradation sequencing and genome mining. While the SNBPs of several of these species exhibit a canonical arginine-rich protamine nature, a few of them exhibit a protamine-like composition. They appear to be the products of extensive cleavage processing from a precursor protein which are sometimes further processed by other post-translational modifications that are likely involved in the chromatin transitions observed during spermiogenesis in these organisms.


Assuntos
Sequência de Aminoácidos , Protaminas , Animais , Masculino , Protaminas/metabolismo , Protaminas/química , Proteínas Nucleares/metabolismo , Proteínas Nucleares/genética , Proteínas de Insetos/metabolismo , Proteínas de Insetos/química , Proteínas de Insetos/genética , Insetos/metabolismo , Dados de Sequência Molecular , Espermatozoides/metabolismo
2.
Langmuir ; 38(23): 7234-7243, 2022 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-35641430

RESUMO

Membrane proteins play essential roles in the cell, and they constitute one of the most important targets of drugs. Studying membrane proteins in a controlled model membrane environment can provide unambiguous, quantitative information on their molecular properties and functions. However, reconstituting membrane proteins in a model system poses formidable technological challenges. Here, we developed a novel model membrane platform for highly sensitive observation of membrane proteins by combining a micropatterned lipid membrane and a nanofluidic channel. A micropatterned model membrane was generated by lithographically integrating a polymerized lipid bilayer and a natural (fluid) lipid bilayer. A nanofluidic channel having a defined thickness was formed between the fluid bilayer and a polydimethylsiloxane (PDMS) slab by attaching the polymeric bilayer and PDMS slab using an adhesion layer composed of silica nanoparticles that are coated with a biocompatible polymer brush. As we reconstituted rhodopsin (Rh), a G-protein-coupled receptor (GPCR), from a detergent-solubilized state into the fluid bilayer, only successfully reconstituted Rh molecules diffused laterally in the lipid bilayer and migrated into the nanogap junction, where they could be observed with a vastly improved signal-to-background ratio. The nanogap junction effectively separates the sites of reconstitution and observation and provides a novel platform for studying the molecular properties and functions of membrane proteins at the single-molecular level.


Assuntos
Bicamadas Lipídicas , Proteínas de Membrana , Membranas/metabolismo , Polimerização , Polímeros , Rodopsina/metabolismo
3.
Cladistics ; 38(3): 374-391, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34818432

RESUMO

The sequential breakup of the supercontinent Pangaea since the Middle Jurassic is one of the crucial factors that has driven the biogeographical patterns of terrestrial biotas. Despite decades of effort searching for concordant patterns between diversification and continental fragmentation among taxonomic groups, increasing evidence has revealed more complex and idiosyncratic scenarios resulting from a mixture of vicariance, dispersal and extinction. Aquatic insects with discreet ecological requirements, low vagility and disjunct distributions represent a valuable model for testing biogeographical hypotheses by reconstructing their distribution patterns and temporal divergences. Insects of the order Megaloptera have exclusively aquatic larvae, their adults have low vagility, and the group has a highly disjunct geographical distribution. Here we present a comprehensive phylogeny of Megaloptera based on a large-scale mitochondrial genome sequencing of 99 species representing >90% of the world genera from all major biogeographical regions. Molecular dating suggests that the deep divergence within Megaloptera pre-dates the breakup of Pangaea. Subsequently, the intergeneric divergences within Corydalinae (dobsonflies), Chauliodinae (fishflies) and Sialidae (alderflies) might have been driven by both vicariance and dispersal correlated with the shifting continent during the Cretaceous, but with strikingly different and incongruent biogeographical signals. The austral distribution of many corydalids appears to be a result of colonization from Eurasia through southward dispersal across Europe and Africa during the Cretaceous, whereas a nearly contemporaneous dispersal via northward rafting of Gondwanan landmasses may account for the colonization of extant Eurasian alderflies from the south.


Assuntos
Genoma Mitocondrial , Holometábolos , Animais , Genoma Mitocondrial/genética , Holometábolos/genética , Insetos/genética , Mitocôndrias/genética , Filogenia
4.
J Bacteriol ; 201(6)2019 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-30642987

RESUMO

The bacterial flagellar motor is composed of a rotor and a dozen stators and converts the ion flux through the stator into torque. Each stator unit alternates in its attachment to and detachment from the rotor even during rotation. In some species, stator assembly depends on the input energy, but it remains unclear how an electrochemical potential across the membrane (e.g., proton motive force [PMF]) or ion flux is involved in stator assembly dynamics. Here, we focused on pH dependence of a slow motile MotA(M206I) mutant of Salmonella The MotA(M206I) motor produces torque comparable to that of the wild-type motor near stall, but its rotation rate is considerably decreased as the external load is reduced. Rotation assays of flagella labeled with 1-µm beads showed that the rotation rate of the MotA(M206I) motor is increased by lowering the external pH whereas that of the wild-type motor is not. Measurements of the speed produced by a single stator unit using 1-µm beads showed that the unit speed of the MotA(M206I) is about 60% of that of the wild-type and that a decrease in external pH did not affect the MotA(M206I) unit speed. Analysis of the subcellular stator localization revealed that the number of functional stators is restored by lowering the external pH. The pH-dependent improvement of stator assembly was observed even when the PMF was collapsed and proton transfer was inhibited. These results suggest that MotA-Met206 is responsible for not only load-dependent energy coupling between the proton influx and rotation but also pH-dependent stator assembly.IMPORTANCE The bacterial flagellar motor is a rotary nanomachine driven by the electrochemical transmembrane potential (ion motive force). About 10 stators (MotA/MotB complexes) are docked around a rotor, and the stator recruitment depends on the load, ion motive force, and coupling ion flux. The MotA(M206I) mutation slows motor rotation and decreases the number of docked stators in Salmonella We show that lowering the external pH improves the assembly of the mutant stators. Neither the collapse of the ion motive force nor a mutation mimicking the proton-binding state inhibited stator localization to the motor. These results suggest that MotA-Met206 is involved in torque generation and proton translocation and that stator assembly is stabilized by protonation of the stator.


Assuntos
Proteínas de Bactérias/metabolismo , Flagelos/fisiologia , Proteínas Motores Moleculares/metabolismo , Proteínas Mutantes/metabolismo , Multimerização Proteica , ATPases Translocadoras de Prótons/metabolismo , Salmonella typhimurium/fisiologia , Concentração de Íons de Hidrogênio , Locomoção , Proteínas Motores Moleculares/genética , Proteínas Mutantes/genética , Mutação de Sentido Incorreto , ATPases Translocadoras de Prótons/genética , Torque
5.
Langmuir ; 35(45): 14696-14703, 2019 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-31613105

RESUMO

Phospholipid bilayers spontaneously spread on a hydrophilic substrate such as glass in aqueous solution due to the energetic gain of surface wetting. This process (self-spreading) was utilized to form a patterned model biological membrane containing reconstituted membrane proteins. A mechanically stable framework of a polymerized lipid bilayer was first generated by the lithographic polymerization of a diacetylene phospholipid. Then, natural lipid membranes (fluid bilayers) were introduced into the channels between polymeric bilayers by the self-spreading from a phospholipid reservoir. The spreading velocity could be fitted into a slope of -0.5 in a double logarithmic plot versus time due to the balance between the spreading force and resistive drag. The preformed polymeric bilayer accelerated the spreading by the energetic gain of covering hydrophobic edges with a lipid bilayer. At the same time, the domains of the polymeric bilayer obstructed spreading, and the spreading velocity linearly decreased with their fractional coverage. Above the critical coverage of ca. 50%, self-spreading was completely blocked (percolation threshold) and the fluid bilayer was confined in the polymer-free regions. Nonspecific adsorption of lipids onto the surface of polymeric bilayers was negligible, which enabled a heightened signal-to-background ratio in the reconstitution and observation of membrane proteins. Self-spread bilayers had a higher density of lipids than those formed by the spontaneous rupture of vesicles (vesicle fusion), presumably due to the continual supply of lipid molecules from the reservoir. These features give the self-spreading important advantages for preparing patterned model membranes with reconstituted membrane proteins.

6.
Foot Ankle Surg ; 25(2): 193-197, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29409287

RESUMO

BACKGROUND: The aims of this study were to identify the artery feeding the fifth metatarsal and determine how bunionette osteotomy could injure this vessel. METHODS: The nutrient artery entering the fifth metatarsal was investigated in 10 adult cadaveric lower limbs by barium injection and enhanced computed tomography. RESULTS: The nutrient artery entered the medial aspect of the fifth metatarsal around the junction of the middle and proximal thirds obliquely from a distal direction (mean angle 36°) in the coronal plane in all cases; in the axial plane, the point of entry and direction of the artery was medial-plantar (mean angle 49°). CONCLUSIONS: This report revealed direction and location of the nutrient artery entering the fifth metatarsal.


Assuntos
Artérias/diagnóstico por imagem , Joanete do Alfaiate/cirurgia , Ossos do Metatarso/irrigação sanguínea , Osteotomia/métodos , Idoso , Joanete do Alfaiate/diagnóstico , Cadáver , Angiografia por Tomografia Computadorizada , Feminino , Humanos , Masculino , Ossos do Metatarso/diagnóstico por imagem , Ossos do Metatarso/cirurgia , Órgãos em Risco
7.
J Biol Chem ; 292(37): 15321-15328, 2017 09 15.
Artigo em Inglês | MEDLINE | ID: mdl-28747438

RESUMO

The visual photopigment rhodopsin (Rh) is a prototypical G protein-coupled receptor (GPCR) responsible for initiation of the phototransduction cascade in rod photoreceptors. Similar to other GPCRs, Rh can form dimers or even higher oligomers and tends to have a supramolecular organization that is likely important in the dim light response. Rh also exhibits high affinity for lipid rafts (i.e. raftophilicity) upon light-dependent binding with the cognate G protein transducin (Gt), suggesting the presence of lipid raft-like domains in the retinal disk membrane and their importance in phototransduction. However, the relationship between Rh oligomerization and lipid rafts in the disk membrane remains to be explored. Given previous findings that Gt binds to dimeric Rh and that Rh is posttranslationally modified with two highly raftophilic palmitoyl moieties, we hypothesized that Rh becomes raftophilic upon dimerization. Here, using biochemical assays, we found that Rh*-Gt complexes in the detergent-resistant membrane are partially resistant to cholesterol depletion by methyl-ß-cyclodextrin and that the Rh-to-Gt stoichiometry in this methyl-ß-cyclodextrin-resistant complex is 2:1. Next, we found that IgG-mediated Rh-Rh cross-linking renders Rh highly raftophilic, supporting the premise that Rh becomes raftophilic upon dimerization. Rh depalmitoylation via reduction of thioester linkages blocked the translocation of IgG-cross-linked Rh to the detergent-resistant membrane, highlighting that the two palmitoyl moieties are important for the dimerization-dependent raftophilicity of Rh. These results indicate that palmitoylated GPCRs such as Rh can acquire raftophilicity upon G protein-stabilized dimerization and thereby organize receptor-cluster rafts by recruiting raftophilic lipids.


Assuntos
Lipoilação , Microdomínios da Membrana/metabolismo , Modelos Moleculares , Processamento de Proteína Pós-Traducional , Rana catesbeiana/fisiologia , Rodopsina/metabolismo , Segmento Externo da Célula Bastonete/metabolismo , Proteínas de Anfíbios/química , Proteínas de Anfíbios/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Cisteína/química , Cistina/química , Adaptação à Escuridão , Dimerização , Interações Hidrofóbicas e Hidrofílicas , Cinética , Luz , Lipoilação/efeitos da radiação , Microdomínios da Membrana/química , Microdomínios da Membrana/efeitos da radiação , Oxirredução , Conformação Proteica/efeitos da radiação , Multimerização Proteica/efeitos da radiação , Processamento de Proteína Pós-Traducional/efeitos da radiação , Estabilidade Proteica/efeitos da radiação , Rodopsina/química , Segmento Externo da Célula Bastonete/química , Segmento Externo da Célula Bastonete/efeitos da radiação , Transducina/química , Transducina/metabolismo
8.
J Foot Ankle Surg ; 57(3): 537-542, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29548631

RESUMO

Arthroscopy is an important and minimally invasive diagnostic and therapeutic tool. However, the risk of injury to the neurovascular structures around the portals exists during arthroscopy of the ankle. In the present study, we measured the distance between each portal and the adjacent neurovascular structures with the foot in plantarflexion and dorsiflexion in the Japanese population. Standard anterolateral (AL), anteromedial, posterolateral (PL), and posteromedial portal positions were identified in 6 fresh adult cadaveric feet. The skin was dissected from the underlying tissue to visualize the adjacent neurovascular structures as noninvasively as possible. The superficial peroneal nerve was the structure closest to an anterior (i.e., AL) portal (3.2 ± 4.2 and 8.3 ± 3.9 mm in plantarflexion and 5.2 ± 4.3 and 10.8 ± 4.1 mm in dorsiflexion), followed by the saphenous nerve and great saphenous vein (SpV). The distance from the superficial peroneal nerve to the AL portal and from the saphenous nerve and great SpV to the anteromedial portal increased significantly with dorsiflexion and decreased significantly with plantarflexion. The sural nerve was the structure closest to the posterior (i.e., PL) portal (10.4 ± 4.8 mm in plantarflexion and 8.5 ± 3.9 mm in dorsiflexion), followed by the lesser SpV. The distance from the sural nerve, saphenous nerve, and lesser SpV to the PL portal and from flexor hallucis longus, posterior tibial artery, and tibial nerve to the posteromedial portal increased significantly in plantarflexion and decreased significantly in dorsiflexion. These findings could help to prevent damage to the neurovascular structures during ankle arthroscopy.


Assuntos
Articulação do Tornozelo/anatomia & histologia , Artroscópios , Artroscopia/métodos , Complicações Intraoperatórias/prevenção & controle , Amplitude de Movimento Articular/fisiologia , Idoso , Idoso de 80 Anos ou mais , Articulação do Tornozelo/cirurgia , Cadáver , Dissecação , Feminino , Humanos , Masculino , Nervo Fibular/anatomia & histologia , Sensibilidade e Especificidade , Nervo Sural/anatomia & histologia , Artérias da Tíbia/anatomia & histologia , Nervo Tibial/anatomia & histologia
9.
Evol Dev ; 19(1): 9-16, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27869366

RESUMO

The evolution of winglessness in insects has been typically interpreted as a consequence of developmental and other adaptations to various environments that are secondarily derived from a winged morph. Several species of bagworm moths (Insecta: Lepidoptera, Psychidae) exhibit a case-dwelling larval life style along with one of the most extreme cases of sexual dimorphism: wingless female adults. While the developmental process that led to these wingless females is well known, the origins and evolutionary transitions are not yet understood. To examine the evolutionary patterns of wing reduction in bagworm females, we reconstruct the molecular phylogeny of over 30 Asian species based on both mitochondrial (cytochrome c oxidase subunit I) and nuclear (28S rRNA) DNA sequences. Under a parsimonious assumption, the molecular phylogeny implies that: (i) the evolutionary wing reduction towards wingless females consisted of two steps: (Step I) from functional wings to vestigial wings (nonfunctional) and (Step II) from vestigial wings to the most specialized vermiform adults (lacking wings and legs); and (ii) vermiform morphs evolved independently at least twice. Based on the results of our study, we suggest that the evolutionary changes in the developmental system are essential for the establishment of different wingless forms in insects.


Assuntos
Evolução Biológica , Mariposas/anatomia & histologia , Mariposas/genética , Asas de Animais/anatomia & histologia , Animais , Feminino , Masculino , Mariposas/classificação , Mariposas/fisiologia , Filogenia , Caracteres Sexuais , Asas de Animais/fisiologia
10.
Langmuir ; 33(23): 5752-5759, 2017 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-28514175

RESUMO

Substrate-supported planar lipid bilayers (SPBs) are being utilized as a versatile model system of the biological membrane. However, the proximity between the solid support and membrane limits utility of SPBs for the functional analyses of membrane proteins. Here, we present a model membrane that can enlarge the distance between the substrate surface and the membrane by combining a stable scaffold of polymerized lipid bilayer with a hydrophilic polymer brush. A micropatterned SPB was generated by the lithographic polymerization of diacetylene lipids and subsequent incorporation of natural (fluid) lipid bilayers. Hydrophilic polymer brush of poly-2-methacryloyloxyethyl phosphorylcholine (poly(MPC)) was formed on the surface of polymeric bilayer by the in situ atom transfer radical polymerization (ATRP) in aqueous solution, in the presence of embedded fluid lipid bilayers. A model membrane protein (Haloquadratum walsbyi bacteriorhodopsin: HwBR) could be reconstituted into the polymer brush-supported bilayers with significantly reduced immobile molecules. Furthermore, the polymer brush terminals could be functionalized by successively polymerizing MPC and 2-aminoethyl methacrylate (AMA). The reactive amine moiety of poly(AMA) enables to conjugate a wide range of biological molecules and surfaces to the membrane. The combination of micropatterned bilayer and polymer brush mimics the two- and three-dimensional structures of the biological membrane, providing a platform to assay membrane proteins in a truly biomimetic environment.


Assuntos
Polímeros/química , Interações Hidrofóbicas e Hidrofílicas , Bicamadas Lipídicas , Proteínas de Membrana , Polimerização
11.
Angew Chem Int Ed Engl ; 56(1): 270-274, 2017 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-27900841

RESUMO

Prod1 is a protein that regulates limb regeneration in salamanders by determining the direction of limb growth. Prod1 is attached to the membrane by a glycosylphosphatidylinositol (GPI) anchor, but the role of membrane anchoring in the limb regeneration process is poorly understood. In this study, we investigated the functional role of the anchoring of Prod1 to the membrane by using its synthetic mimics in combination with solid-state NMR spectroscopy and fluorescent microscopy techniques. Anchoring did not affect the three-dimensional structure of Prod1 but did induce aggregation by aligning the molecules and drastically reducing the molecular motion on the two-dimensional membrane surface. Interestingly, aggregated Prod1 interacted with Prod1 molecules tethered on the surface of opposing membranes, inducing membrane adhesion. Our results strongly suggest that anchoring of the salamander-specific protein Prod1 assists cell adhesion in the limb regeneration process.


Assuntos
Proteínas de Anfíbios/metabolismo , Extremidades/crescimento & desenvolvimento , Glicosilfosfatidilinositóis/metabolismo , Regeneração , Salamandridae/metabolismo , Proteínas de Anfíbios/química , Animais , Glicosilfosfatidilinositóis/química , Microscopia de Fluorescência , Ressonância Magnética Nuclear Biomolecular
12.
Zoolog Sci ; 33(5): 476-484, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27715415

RESUMO

Salamanders are expected to differentiate genetically among local populations due to their low dispersal ability, and are potentially susceptible to loss of genetic diversity if the population is isolated by habitat fragmentation. The salamander Hynobius tokyoensis is a lowland lentic breeder and endemic to a narrow area of central Japan. In this urban area, H. tokyoensis habitats are extensively fragmented and several populations are threatened with extinction, but information on genetic divergence and loss of genetic diversity is scarce. We performed mitochondrial (cyt b) and microsatellite (five loci) DNA analyses of 815 individuals from 46 populations in 12 regions across their entire distribution range. As a result, populations were clearly separated into northern and southern groups, and genetic differentiation among the 12 regions was also evident. Regional differentiation appears to be affected by a complex geographical history, but the genetic diversity of each population may have also been affected by recent habitat fragmentation. There were positive correlations between the mitochondrial and microsatellite DNA diversities. Some populations have lost genetic diversity in both mitochondrial and microsatellite DNAs; all such populations were at the peripheral edges of the species distribution range. Thus, even in attempts to restore genetic diversity in a small population by the transfer of outside individuals, efforts must be made to avoid genetic pollution.


Assuntos
Variação Genética , Urodelos/genética , Distribuição Animal , Grupos de População Animal , Animais , DNA Mitocondrial/genética , Ecossistema , Feminino , Repetições de Microssatélites , Filogenia , Tóquio , Urodelos/fisiologia
13.
Biophys J ; 109(11): 2307-16, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26636942

RESUMO

Lipid rafts in the cell membrane are believed to affect various membrane functions, including the signaling by G-protein coupled receptors (GPCRs). However, the regulatory roles of lipid rafts on GPCRs' functions are still poorly understood, partially owing to the lack of the methods to quantitatively evaluate the affinity of membrane proteins to lipid raft (raftophilicity). Here, we describe a methodology to gauge the raftophilicity of a representative GPCR in vertebrate photoreceptor, i.e., rhodopsin (Rh), and its cognate G protein transducin (Gt) by using a patterned model membrane. We generated a substrate-supported planar lipid bilayer that has patterned regions of liquid-ordered (Lo) and liquid-disordered (Ld) membrane domains. We reconstituted Rh and Gt into the patterned membrane and observed their lateral distribution and diffusion. Mobile and functional Rh molecules could be reconstituted through the rapid dilution of solubilized Rh, by optimizing the reconstitution conditions including the chamber design, protein/detergent concentrations, and solution mixing. We determined the partition and diffusion coefficients of Rh and Gt in the Lo-rich and Ld-rich regions. Both Rh and Gt were predominantly localized in the Ld phase, suggesting their low affinity to lipid rafts. Patterned model membrane offers a robust and scalable platform for systematically and quantitatively studying the functional roles of lipid rafts in biological membranes including retinal disk membranes.


Assuntos
Microdomínios da Membrana/metabolismo , Modelos Biológicos , Rodopsina/metabolismo , Difusão , Bicamadas Lipídicas/metabolismo , Ligação Proteica , Transporte Proteico , Transducina/metabolismo
14.
J Neurosci Res ; 93(9): 1462-70, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25981177

RESUMO

Neurons have well-developed membrane microdomains called "rafts" that are recovered as a detergent-resistant membrane microdomain fraction (DRM). Neuronal tissue-enriched acidic protein of 22 kDa (NAP-22) is one of the major protein components of neuronal DRM. To determine the cellular function of NAP-22, interacting proteins were screened with an immunoprecipitation assay, and calcineurin (CaN) was detected. Further studies with NAP-22 prepared from DRM and CaN expressed in bacteria showed the binding of these proteins and a dose-dependent inhibitory effect of the NAP-22 fraction on the phosphatase activity of CaN. On the other hand, NAP-22 expressed in bacteria showed low binding to CaN and a weak inhibitory effect on phosphatase activity. To solve this discrepancy, identification of a nonprotein component that modulates CaN activity in the DRM-derived NAP-22 fraction was attempted. After lyophilization, a lipid fraction was extracted with chloroform/methanol. The lipid fraction showed an inhibitory effect on CaN without NAP-22, and further fractionation of the extract with thin-layer chromatography showed the presence of several lipid bands having an inhibitory effect on CaN. The mobility of these bands coincided with that of authentic ganglioside (GM1a, GD1a, GD1b, and GT1b), and authentic ganglioside showed an inhibitory effect on CaN. Treatment of lipid with endoglycoceramidase, which degrades ganglioside to glycochain and ceramide, caused a diminution of the inhibitory effect. These results show that DRM-derived NAP-22 binds several lipids, including ganglioside, and that ganglioside inhibits the phosphatase activity of CaN.


Assuntos
Encéfalo/citologia , Calcineurina/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Proteínas do Citoesqueleto/metabolismo , Gangliosídeos/metabolismo , Microdomínios da Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Animais , Proteínas de Ligação a Calmodulina/química , Células Cultivadas , Cromatografia em Camada Fina , Proteínas do Citoesqueleto/química , Detergentes/farmacologia , Gangliosídeos/química , Glicosídeo Hidrolases/farmacologia , Imunoprecipitação , Metabolismo dos Lipídeos/efeitos dos fármacos , Microdomínios da Membrana/efeitos dos fármacos , Proteínas do Tecido Nervoso/química , Neurônios/metabolismo , Neurônios/ultraestrutura , Monoéster Fosfórico Hidrolases/metabolismo , Ratos , Ratos Wistar
15.
Proc Biol Sci ; 282(1807): 20150247, 2015 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-25925103

RESUMO

Many male animals have evolved exaggerated traits that they use in combat with rival males to gain access to females and secure their reproductive success. But some male animals invest in nuptial gifts that gains them access to females. Both these reproductive strategies are costly in that resources are needed to produce the weapon or nuptial gift. In closely related species where both weapons and nuptial gifts are present, little is known about the potential evolutionary trade-off faced by males that have these traits. In this study, we use dobsonflies (order Megaloptera, family Corydalidae, subfamily Corydalinae) to examine the presence and absence of enlarged male weapons versus nuptial gifts within and among species. Many dobsonfly species are sexually dimorphic, and males possess extremely enlarged mandibles that they use in battles, whereas in other species, males produce large nuptial gifts that increase female fecundity. In our study, we show that male accessory gland size strongly correlates with nuptial gift size and that when male weapons are large, nuptial gifts are small and vice versa. We mapped weapons and nuptial gifts onto a phylogeny we constructed of 57 species of dobsonflies. Our among-species comparison shows that large nuptial gift production evolved in many species of dobsonfly but is absent from those with exaggerated weapons. This pattern supports the potential explanation that the trade-off in resource allocation between weapons and nuptial gifts is important in driving the diversity of male mating strategies seen in the dobsonflies, whereas reduced male-male competition in the species producing large spermatophores could be an alternative explanation on their loss of male weapons. Our results shed new light on the evolutionary interplay of multiple sexually selected traits in animals.


Assuntos
Insetos/anatomia & histologia , Animais , Evolução Biológica , Glândulas Exócrinas/anatomia & histologia , Feminino , Masculino , Mandíbula/anatomia & histologia , Filogenia , Caracteres Sexuais , Comportamento Sexual Animal , Especificidade da Espécie , Espermatogônias/citologia
16.
Cladistics ; 31(1): 18-49, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34758581

RESUMO

Sialidae (alderflies) is a family of the holometabolous insect order Megaloptera, with ca. 75 extant species in eight genera distributed worldwide. Alderflies are a group of "living fossils" with a long evolutionary history. The oldest fossil attributed to Sialidae dates back to the Early Jurassic period. Further, the global distribution of modern-day species shows a remarkably disjunctive pattern. However, due to the rareness of most species and scarcity of comprehensive taxonomic revisions, the phylogeny of Sialidae remains largely unexplored, and the present classification system is in great need of renewal. Here we reconstruct the first phylogeny for Sialidae worldwide based on the most comprehensive sampling and broadest morphological data ever presented for this group of insects. All Cenozoic alderflies belong to a monophyletic clade, which may also include the Early Jurassic genus †Dobbertinia, and the Late Jurassic genus †Sharasialis is their putative sister taxon. Two subfamilies of Sialidae are proposed, namely †Sharasialinae subfam. nov. and Sialidinae. Austrosialis is the sister of all other extant genera, an assemblage which comprises three monophyletic lineages: the Stenosialis lineage, the Ilyobius lineage, and the Sialis lineage. The revised classification of Sialidae is composed of 12 valid genera and 87 valid species. Ilyobius and Protosialis are recognized as valid generic names, while Nipponosialis is treated as a synonym of Sialis. Reconstruction of the ancestral area proposes a global distribution of alderflies in Pangaea before their diversification. The generic diversification of alderflies might have occurred before the breakup of Pangaea, but the divergence of some lineages or genera was probably promoted by the splitting of this supercontinent.

17.
Zoolog Sci ; 32(1): 47-52, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25660696

RESUMO

DNA analysis can reveal the origins and dispersal patterns of invasive species. The green anole Anolis carolinensis is one such alien animal, which has been dispersed widely by humans from its native North America to many Pacific Ocean islands. In the Ogasawara (Bonin) Islands, this anole was recorded from Chichi-jima at the end of the 1960s, and then from Haha-jima in the early 1980s. These two islands are inhabited. In 2013, it was also found on the uninhabited Ani-jima, close to Chichi-jima. Humans are thought to have introduced the anole to Haha-jima, while the mode of introduction to Ani-jima is unknown. To clarify its dispersal patterns within and among these three islands, we assessed the fine-scale population genetic structure using five microsatellite loci. The results show a homogeneous genetic structure within islands, but different genetic structures among islands, suggesting that limited gene flow occurs between islands. The recently established Ani-jima population may have originated from several individuals simultaneously, or by repeated immigration from Chichi-jima. We must consider frequent incursions among these islands to control these invasive lizard populations and prevent their negative impact on native biodiversity.


Assuntos
Espécies Introduzidas , Lagartos/genética , Repetições de Microssatélites , Animais , DNA Mitocondrial/genética , Feminino , Haplótipos , Japão , Masculino
18.
Biochim Biophys Acta ; 1832(10): 1549-59, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23712071

RESUMO

Recent studies have suggested a possible involvement of abnormal tau in some retinal degenerative diseases. The common view in these studies is that these retinal diseases share the mechanism of tau-mediated degenerative diseases in brain and that information about these brain diseases may be directly applied to explain these retinal diseases. Here we collectively examine this view by revealing three basic characteristics of tau in the rod outer segment (ROS) of bovine retinal photoreceptors, i.e., its isoforms, its phosphorylation mode and its interaction with microtubules, and by comparing them with those of brain tau. We find that ROS contains at least four isoforms: three are identical to those in brain and one is unique in ROS. All ROS isoforms, like brain isoforms, are modified with multiple phosphate molecules; however, ROS isoforms show their own specific phosphorylation pattern, and these phosphorylation patterns appear not to be identical to those of brain tau. Interestingly, some ROS isoforms, under the normal conditions, are phosphorylated at the sites identical to those in Alzheimer's patient isoforms. Surprisingly, a large portion of ROS isoforms tightly associates with a membranous component(s) other than microtubules, and this association is independent of their phosphorylation states. These observations strongly suggest that tau plays various roles in ROS and that some of these functions may not be comparable to those of brain tau. We believe that knowledge about tau in the entire retinal network and/or its individual cells are also essential for elucidation of tau-mediated retinal diseases, if any.


Assuntos
Encéfalo/metabolismo , Segmento Externo das Células Fotorreceptoras da Retina/metabolismo , Segmento Externo da Célula Bastonete/metabolismo , Proteínas tau/metabolismo , Animais , Bovinos , Eletroforese em Gel Bidimensional , Fosforilação , Isoformas de Proteínas/metabolismo
19.
Biosci Biotechnol Biochem ; 78(9): 1560-3, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25209503

RESUMO

SptP is a virulence effector protein of Salmonella that is involved in bacterial invasion into a host cell. For effective secretion, SptP forms a complex with SptP-specific chaperone SicP through its chaperone-binding domain, residues 35-139. Here, we suggest the possibility that residues 106-136 of SptP are important for complex formation with SicP by in vitro reconstitution experiments.


Assuntos
Proteínas de Bactérias/química , Chaperonas Moleculares/química , Proteínas Tirosina Fosfatases/química , Infecções por Salmonella/microbiologia , Salmonella typhimurium/química , Proteínas de Bactérias/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Chaperonas Moleculares/metabolismo , Ligação Proteica , Estrutura Terciária de Proteína , Proteínas Tirosina Fosfatases/metabolismo , Infecções por Salmonella/genética , Salmonella typhimurium/patogenicidade
20.
Zootaxa ; (3796): 320-36, 2014 May 19.
Artigo em Inglês | MEDLINE | ID: mdl-24870678

RESUMO

The Megaloptera fauna of Madagascar comprise two endemic genera: Haplosialis Navás, 1927 (Sialidae) and Madachauliodes Paulian, 1951 (Corydalidae: Chauliodinae). Here the two genera are revised, with detailed descriptions and illustrations. A new species, Madachauliodes bicuspidatus Liu, Price & Hayashi, sp. nov., is described. Furthermore the phylogeny and biogeography of the Madagascan fauna is discussed.


Assuntos
Insetos/classificação , Animais , Feminino , Geografia , Insetos/anatomia & histologia , Madagáscar , Masculino , Filogenia , Especificidade da Espécie
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