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1.
Front Immunol ; 15: 1333170, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38545112

RESUMEN

Hypertensive nephropathy (HTN) is the second leading cause of end-stage renal disease (ESRD) and a chronic inflammatory disease. Persistent hypertension leads to lesions of intrarenal arterioles and arterioles, luminal stenosis, secondary ischemic renal parenchymal damage, and glomerulosclerosis, tubular atrophy, and interstitial fibrosis. Studying the pathogenesis of hypertensive nephropathy is a prerequisite for diagnosis and treatment. The main cause of HTN is poor long-term blood pressure control, but kidney damage is often accompanied by the occurrence of immune inflammation. Some studies have found that the activation of innate immunity, inflammation and acquired immunity is closely related to the pathogenesis of HTN, which can cause damage and dysfunction of target organs. There are more articles on the mechanism of diabetic nephropathy, while there are fewer studies related to immunity in hypertensive nephropathy. This article reviews the mechanisms by which several different immune cells and inflammatory cytokines regulate blood pressure and renal damage in HTN. It mainly focuses on immune cells, cytokines, and chemokines and inhibitors. However, further comprehensive and large-scale studies are needed to determine the role of these markers and provide effective protocols for clinical intervention and treatment.


Asunto(s)
Hipertensión Renal , Nefritis , Humanos , Inflamación , Citocinas
2.
Front Neurosci ; 17: 1203915, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37539383

RESUMEN

Autoimmune encephalitis, a class of encephalitis, is clinically characterized by multifocal or diffuse brain injury, including aberrant mental behavior, convulsions, and near-event memory impairment. In this article, we describe a female patient with autoimmune encephalitis who tested positive for leucine-rich glioma inactivated 1 (LGI1) antibodies and had hippocampal inflammatory edema in the lesion area. During the first 3 months of her illness, the patient primarily experienced memory loss, the onset of rigid twitching in her extremities that lasted for 1 min while in remission, and incontinence. After gamma globulin administration, methylprednisolone shock, and other symptomatic therapies during hospitalization, the patient's psychiatric symptoms and seizures improved considerably; however, she did not fully recover her memory. After receiving fire acupuncture for 6 months, the patient's understanding, orientation, and calculation skills improved considerably. Her memory and mental state were also improved at the follow-up visit. In this case, the use of fire acupuncture for the treatment of autoimmune encephalitis resulted in favorable outcomes with important benefits for conditions affecting the central nervous system; however, more convincing data are required to support the effectiveness of this treatment method.

3.
Front Neurosci ; 17: 1161578, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37304030

RESUMEN

Aim: To observe the effects of acupuncture manipulations on blood pressure and brain function in spontaneously hypertensive rats and elucidate the anti-hypertensive effect of the manipulations' central mechanism. Methods: This study used acupuncture twirling reinforcing, acupuncture twirling reducing, and acupuncture twirling uniform reinforcing-reducing manipulations to act on the bilateral TaiChong point of rats. The depth of acupuncture was 1.5-2 mm, and twisting was performed at a frequency of 60 times/min within ±360° for 3 min, followed by the needle being retained for 17 min. Functional magnetic resonance imaging was performed at the end of the intervention. Regional homogeneity and amplitude of low-frequency fluctuations were used to assess the differences in brain regions in each group of rats, and the core brain region (left hypothalamus) among the differential brain regions was selected as the seed for functional connectivity analysis. Results: (1) The anti-hypertensive effect was achieved by acupuncture manipulations, and the anti-hypertensive effect of twirling reducing manipulation on spontaneously hypertensive rats was better than that of twirling uniform reinforcing-reducing and twirling reinforcing manipulations. (2) After regional homogeneity and amplitude of low-frequency fluctuations analyses, the hypothalamus, the brain region related to blood pressure, was activated in the twirling uniform reinforcing-reducing manipulation group; the corpus callosum and cerebellum were activated in the twirling reinforcing manipulation group; and the hypothalamus, olfactory bulb, corpus callosum, brainstem, globus pallidum, and striatum were activated in the twirling reducing manipulation group. (3) According to the functional connectivity analysis, different acupuncture manipulations increased the functional connections between seed points and the brainstem, olfactory bulb, and cerebellum, etc. Conclusion: These results suggest that acupuncture manipulations achieved the hypotensive effect and the twirling reducing manipulation had a better hypotensive effect on spontaneously hypertensive rats than twirling uniform reinforcing-reducing and twirling reinforcing manipulations; the central mechanism of the anti-hypertensive effect of twirling reinforcing and reducing manipulation may be related to the activation of brain regions associated with blood pressure regulation and the functional connections between them. Furthermore, brain regions involved in motor control, cognition, and hearing were also activated. We hypothesize that activation of these brain regions may help prevent or mitigate the onset and progression of hypertensive brain damage.

4.
Front Neurosci ; 17: 1129688, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36968479

RESUMEN

Introduction: Chronic hypertension may have a contributory role toward cognitive impairment. Acupuncture exerts protective effects on cognitive functions while controlling the blood pressure. However, the neural mechanism underlying the dual attenuating effect of acupuncture remains unclear. In this study, we investigated the effects of electroacupuncture (EA) and manual acupuncture (MA) on the functional activity of the brain regions of spontaneously hypertensive rats (SHRs) by through resting-state functional magnetic resonance imaging (rs-fMRI). We also evaluated the differences in these functional activities between the EA and MA groups. Methods: We randomly assigned 30 SHRs into the EA, MA, and model (SHR) groups. Wistar Kyoto rats (n = 10) were used as normal control (WKY). The interventions were administered once every alternate day for 12 weeks. The systolic blood pressure of all rats was recorded every 2 weeks until the end of the intervention. After the intervention, rs-fMRI scanning was performed to access the whole brain data of rats randomly selected from each group evenly. The amplitude of low frequency fluctuation (ALFF) analysis, regional homogeneity (ReHo) analysis, and functional connectivity (FC) analysis were also conducted. The Morris water maze (MWM) test was conducted to evaluate the learning and memory of the rats. Hematoxylin-eosin staining and Nissl staining were performed to observe histopathological changes in the key brain regions. Results: We demonstrated that, when compared with the SHR group, the EA and MA groups had significantly lower blood pressure and better performance for behavioral test indices, and that the effect of EA was better than that of MA. ALFF and ReHo analyses revealed enhancement of the neuronal activity of some functionally impaired brain areas in the EA and MA groups. The main callback brain regions included the hypothalamus, entorhinal cortex, brain stem, prelimbic cortex, cingulate cortex, corpus callosum, and cerebellum. The FC analysis demonstrated that EA and MA enhanced the functional connectivity between the seeds and brain regions such as the brain stem, entorhinal cortex, hippocampus, prelimbic cortex, and cerebellum. The pathological test of the entorhinal cortex also verified the protective effect of acupuncture on the neuronal functional activity. Discussion: Our findings suggested that EA and MA exhibited attenuating effects on hypertension and cognitive dysfunction by enhancing the functional activities in the corresponding brain regions. Moreover, EA activated more callback brain regions and functional connectivity than MA, which may explain why the effect of EA was better than that of MA.

5.
Drug Des Devel Ther ; 16: 4061-4076, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36448035

RESUMEN

Background: Triptolide, a major active ingredient isolated from Tripterygium wilfordii Hook f., is effective in the treatment of membranous nephropathy (MN); however, its pharmacological mechanism of action has not yet been clarified. We applied an approach that integrated network pharmacology and experimental validation to systemically reveal the molecular mechanism of triptolide in the treatment of MN. Methods: First, potential targets of triptolide and the MN-related targets were collected from publicly available database. Then, based on a protein-protein interaction network as well as GO and KEGG pathway enrichment analyses, we constructed target-pathway networks to unravel therapeutic targets and pathways. Moreover, molecular docking was applied to validate the interactions between the triptolide and hub targets. Finally, we induced passive Heymann nephritis (PHN) rat models and validated the possible molecular mechanisms of triptolide against MN. Results: The network pharmacology results showed that 118 intersected targets were identified for triptolide against MN, including mTOR, STAT3, CASP3, EGFR and AKT1. Based on enrichment analysis, signaling pathways such as PI3K/AKT, MAKP, Ras and Rap1 were involved in triptolide treatment of MN. Furthermore, molecular docking confirmed that triptolide could bind with high affinity to the PIK3R1, AKT1 and mTOR, respectively. Then, in vivo experiments indicated that triptolide can reduce 24 h urine protein (P < 0.01) and protect against renal damage in PHN. Serum albumin level was significantly increased and total cholesterol, triglycerides, and low-density lipoprotein levels were decreased by triptolide (P < 0.05). Compared with PHN group, triptolide treatment regulated the PI3K/AKT/mTOR pathway according to Western blot analyses. Conclusion: Triptolide could exert antiproteinuric and renoprotective effects in PHN. The therapeutic mechanism of triptolide may be associated with the regulation of PI3K/AKT/mTOR signaling pathway. This study demonstrates the pharmacological mechanism of triptolide in the treatment of MN and provides scientific evidence for basic and clinical research.


Asunto(s)
Glomerulonefritis Membranosa , Animales , Ratas , Glomerulonefritis Membranosa/tratamiento farmacológico , Simulación del Acoplamiento Molecular , Farmacología en Red , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Serina-Treonina Quinasas TOR
6.
Development ; 149(17)2022 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-36052695

RESUMEN

Stomata are epidermal pores that control gas exchange between plants and the atmosphere. In Arabidopsis, the ERECTA family (ERECTAf) receptors, including ERECTA, ERECTA-LIKE 1 (ERL1) and ERL2, redundantly play pivotal roles in enforcing the 'one-cell-spacing' rule. Accumulating evidence has demonstrated that the functional specificities of receptors are likely associated with their differential subcellular dynamics. The endoplasmic reticulum (ER)-resident chaperone complex SDF2-ERdj3B-BiP functions in many aspects of plant development. We employed pharmacological treatments combined with cell biological and biochemical approaches to demonstrate that the abundance of ERECTA was reduced in the erdj3b-1 mutant, but the localization and dynamics of ERECTA were not noticeably affected. By contrast, the erdj3b mutation caused the retention of ERL1/ERL2 in the ER. Furthermore, we found that the function of SDF2-ERdj3B-BiP is implicated with the distinct roles of ERECTAf receptors. Our findings establish that the ERECTAf receptor-mediated signaling in stomatal development is ensured by the activities of the ER quality control system, which preferentially maintains the protein abundance of ERECTA and proper subcellular dynamics of ERL1/ERL2, prior to the receptors reaching their destination - the plasma membrane - to execute their functions.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Portadoras/metabolismo , Retículo Endoplásmico/metabolismo , Regulación de la Expresión Génica de las Plantas , Proteínas del Choque Térmico HSP40/genética , Proteínas del Choque Térmico HSP40/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas Serina-Treonina Quinasas , Receptores de Superficie Celular/genética
7.
Plant Cell ; 34(10): 3665-3684, 2022 09 27.
Artículo en Inglés | MEDLINE | ID: mdl-35897146

RESUMEN

The endoplasmic reticulum-localized DnaJ family 3B (ERdj3B), is a component of the stromal cell-derived factor 2 (SDF2)-ERdj3B-binding immunoglobulin protein (BiP) chaperone complex, which functions in protein folding, translocation, and quality control. We found that ERdj3B mutations affected integument development in the Ler ecotype but not in the Col-0 ecotype of Arabidopsis (Arabidopsis thaliana). Map-based cloning identified the ERECTA (ER) gene as a natural modifier of ERdj3B. The double mutation of ERdj3B and ER caused a major defect in the inner integument under heat stress. Additional mutation of the ER paralog ERECTA-LIKE 1 (ERL1) or ERL2 to the erdj3b er double mutant exacerbated the defective integument phenotype. The double mutation of ER and SDF2, the other component of the SDF2-ERdj3B-BiP complex, resulted in similar defects in the inner integument. Furthermore, both the protein abundance and plasma membrane partitioning of ER, ERL1, and ERL2 were markedly reduced in erdj3b plants, indicating that the SDF2-ERdj3B-BiP chaperone complex might control the translocation of ERECTA-family proteins from the endoplasmic reticulum to the plasma membrane. Our results suggest that the SDF2-ERdj3B-BiP complex functions in ovule development and the heat stress response in coordination with ERECTA-family receptor kinases.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas Portadoras/metabolismo , Proteínas del Choque Térmico HSP40/metabolismo , Respuesta al Choque Térmico , Óvulo Vegetal/metabolismo , Proteínas Serina-Treonina Quinasas
8.
New Phytol ; 212(3): 730-744, 2016 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-27375201

RESUMEN

Angiosperms and gymnosperms are two major groups of extant seed plants. It has been suggested that gymnosperms lack FLOWERING LOCUS T (FT), a key integrator at the core of flowering pathways in angiosperms. Taking advantage of newly released gymnosperm genomes, we revisited the evolutionary history of the plant phosphatidylethanolamine-binding protein (PEBP) gene family through phylogenetic reconstruction. Expression patterns in three gymnosperm taxa and heterologous expression in Arabidopsis were studied to investigate the functions of gymnosperm FT-like and TERMINAL FLOWER 1 (TFL1)-like genes. Phylogenetic reconstruction suggests that an ancient gene duplication predating the divergence of seed plants gave rise to the FT and TFL1 genes. Expression patterns indicate that gymnosperm TFL1-like genes play a role in the reproductive development process, while GymFT1 and GymFT2, the FT-like genes resulting from a duplication event in the common ancestor of gymnosperms, function in both growth rhythm and sexual development pathways. When expressed in Arabidopsis, both spruce FT-like and TFL1-like genes repressed flowering. Our study demonstrates that gymnosperms do have FT-like and TFL1-like genes. Frequent gene and genome duplications contributed significantly to the expansion of the plant PEBP gene family. The expression patterns of gymnosperm PEBP genes provide novel insight into the functional evolution of this gene family.


Asunto(s)
Cycadopsida/genética , Evolución Molecular , Flores/genética , Genes de Plantas , Familia de Multigenes , Proteínas de Unión a Fosfatidiletanolamina/genética , Proteínas de Plantas/genética , Secuencia de Aminoácidos , Arabidopsis/genética , Dosificación de Gen , Regulación de la Expresión Génica de las Plantas , Funciones de Verosimilitud , Fenotipo , Proteínas de Unión a Fosfatidiletanolamina/química , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Plantas Modificadas Genéticamente
9.
J Integr Plant Biol ; 58(7): 679-92, 2016 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-26699939

RESUMEN

In flowering plants, pollen tube growth is essential for delivery of male gametes into the female gametophyte or embryo sac for double fertilization. Although many genes have been identified as being involved in the process, the molecular mechanisms of pollen tube growth remains poorly understood. In this study, we identified that the Arabidopsis Transmembrane Protein 18 (AtTMEM18) gene played important roles in pollen tube growth. The AtTMEM18 shares a high similarity with the Transmembrane 18 proteins (TMEM18s) that are conserved in most eukaryotes and may play important roles in obesity in humans. Mutation in the AtTMEM18 by a Ds insertion caused abnormal callose deposition in the pollen grains and had a significant impact on pollen germination and pollen tube growth. AtTMEM18 is expressed in pollen grains, pollen tubes, root tips and other vegetative tissues. The pollen-rescued assays showed that the mutation in AtTMEM18 also caused defects in roots, stems, leaves and transmitting tracts. AtTMEM18-GFP was located around the nuclei. Genetic assays demonstrated that the localization of AtTMEM18 around the nuclei in the generative cells of pollen grains was essential for the male fertility. Furthermore, expression of the rice TMEM18-homologous protein (OsTMEM18) driven by LAT52 promoter could recover the fertility of the Arabidopsis attmem18 mutant. These results suggested that the TMEM18 is important for plant growth in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de la Membrana/metabolismo , Tubo Polínico/crecimiento & desarrollo , Tubo Polínico/metabolismo , Secuencia de Aminoácidos , Arabidopsis/genética , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/genética , Núcleo Celular/metabolismo , Proliferación Celular , Regulación de la Expresión Génica de las Plantas , Prueba de Complementación Genética , Germinación , Proteínas Fluorescentes Verdes/metabolismo , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Mutación/genética , Oryza/genética , Fenotipo , Plantas Modificadas Genéticamente , Fracciones Subcelulares/metabolismo
10.
Nat Commun ; 6: 8822, 2015 Nov 18.
Artículo en Inglés | MEDLINE | ID: mdl-26578169

RESUMEN

PIN proteins are auxin export carriers that direct intercellular auxin flow and in turn regulate many aspects of plant growth and development including responses to environmental changes. The Arabidopsis R2R3-MYB transcription factor FOUR LIPS (FLP) and its paralogue MYB88 regulate terminal divisions during stomatal development, as well as female reproductive development and stress responses. Here we show that FLP and MYB88 act redundantly but differentially in regulating the transcription of PIN3 and PIN7 in gravity-sensing cells of primary and lateral roots. On the one hand, FLP is involved in responses to gravity stimulation in primary roots, whereas on the other, FLP and MYB88 function complementarily in establishing the gravitropic set-point angles of lateral roots. Our results support a model in which FLP and MYB88 expression specifically determines the temporal-spatial patterns of PIN3 and PIN7 transcription that are closely associated with their preferential functions during root responses to gravity.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Gravitropismo/genética , Raíces de Plantas/crecimiento & desarrollo , ARN Mensajero/metabolismo , Factores de Transcripción/genética , Arabidopsis/crecimiento & desarrollo , Inmunoprecipitación de Cromatina , Ensayo de Cambio de Movilidad Electroforética , Glucuronidasa/metabolismo , Hibridación in Situ , Organismos Modificados Genéticamente , Raíces de Plantas/metabolismo , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Transcripción Genética
11.
Mol Plant ; 8(5): 783-95, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25680231

RESUMEN

The initiation of stomatal lineage and subsequent asymmetric divisions in Arabidopsis require the activity of the basic helix-loop-helix transcription factor SPEECHLESS (SPCH). It has been shown that SPCH controls entry into the stomatal lineage as a substrate either of the MITOGEN-ACTIVATED PROTEIN KINASE (MAPK) cascade or GSK3-like kinase BRASSINOSTEROID INSENSITIVE 2 (BIN2). Here we show that three serine residues of SPCH appear to be the primary phosphorylation targets of Cyclin-Dependent Kinases A;1 (CDKA;1) in vitro, and among them Serine 186 plays a crucial role in stomatal formation. Expression of an SPCH construct harboring a mutation that results in phosphorylation deficiencies on Serine 186 residue failed to rescue stomatal defects in spch null mutants. Expression of a phosphorylation-mimic mutant SPCH(S186D) complemented stomatal production defects in the transgenic lines harboring the targeted expression of dominant-negative CDKA;1.N146. Therefore, in addition to MAPK- and BIN2-mediated phosphorylation on SPCH, phosphorylation at Serine 186 is positively required for SPCH function in regulating stomatal development.


Asunto(s)
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/química , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/metabolismo , Estomas de Plantas/crecimiento & desarrollo , Serina/metabolismo , Secuencias de Aminoácidos , Arabidopsis/química , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Regulación de la Expresión Génica de las Plantas , Fosforilación , Estomas de Plantas/química , Estomas de Plantas/genética , Estomas de Plantas/metabolismo , Serina/química , Serina/genética
12.
Nat Commun ; 5: 3090, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24463772

RESUMEN

Stomata are two-celled valves that control epidermal pores whose spacing optimizes shoot-atmosphere gas exchange. They develop from protodermal cells after unequal divisions followed by an equal division and differentiation. The concentration of the hormone auxin, a master plant developmental regulator, is tightly controlled in time and space, but its role, if any, in stomatal formation is obscure. Here dynamic changes of auxin activity during stomatal development are monitored using auxin input (DII-VENUS) and output (DR5:VENUS) markers by time-lapse imaging. A decrease in auxin levels in the smaller daughter cell after unequal division presages the acquisition of a guard mother cell fate whose equal division produces the two guard cells. Thus, stomatal patterning requires auxin pathway control of stem cell compartment size, as well as auxin depletion that triggers a developmental switch from unequal to equal division.


Asunto(s)
Tipificación del Cuerpo , Ácidos Indolacéticos/metabolismo , Estomas de Plantas/crecimiento & desarrollo , Proteínas de Arabidopsis/metabolismo , Transporte Biológico , Proteínas Fluorescentes Verdes/metabolismo , Factores de Intercambio de Guanina Nucleótido/metabolismo , Modelos Biológicos , Mutación , Estomas de Plantas/ultraestructura
13.
J Exp Bot ; 62(14): 5161-77, 2011 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-21765162

RESUMEN

The cell wall is important for pollen tube growth, but little is known about the molecular mechanism that controls cell wall deposition in pollen tubes. Here, the functional characterization of the pollen-expressed Arabidopsis cellulose synthase-like D genes CSLD1 and CSLD4 that are required for pollen tube growth is reported. Both CSLD1 and CSLD4 are highly expressed in mature pollen grains and pollen tubes. The CSLD1 and CSLD4 proteins are located in the Golgi apparatus and transported to the plasma membrane of the tip region of growing pollen tubes, where cellulose is actively synthesized. Mutations in CSLD1 and CSLD4 caused a significant reduction in cellulose deposition in the pollen tube wall and a remarkable disorganization of the pollen tube wall layers, which disrupted the genetic transmission of the male gametophyte. In csld1 and csld4 single mutants and in the csld1 csld4 double mutant, all the mutant pollen tubes exhibited similar phenotypes: the pollen tubes grew extremely abnormally both in vitro and in vivo, which indicates that CSLD1 and CSLD4 are not functionally redundant. Taken together, these results suggest that CSLD1 and CSLD4 play important roles in pollen tube growth, probably through participation in cellulose synthesis of the pollen tube wall.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/metabolismo , Celulosa/metabolismo , Glucosiltransferasas/metabolismo , Tubo Polínico/crecimiento & desarrollo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Glucosiltransferasas/genética , Polen/genética , Polen/metabolismo , Tubo Polínico/genética , Tubo Polínico/metabolismo
14.
Plant J ; 65(4): 647-60, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21288267

RESUMEN

In flowering plants, the growth of pollen tubes is essential for the delivery of sperm to the egg cells. Although many factors (including cell-wall properties) are involved in this process, little is known about the underlying molecular mechanisms that regulate the growth of pollen tubes. We report here the characterization of an Arabidopsis mutant male gametophyte defective 4 (mgp4) that is severely defective in pollen tube growth. The mgp4 mutation also impairs root growth of pollen-rescued mgp4 mutant plants generated by expressing MGP4 cDNA under the control of a pollen grain/tube-specific promoter. The MGP4 gene encodes a putative xylosyltransferase and is expressed in many organs/tissues, including pollen tubes and roots. MGP4 protein expressed in Pichia pastoris exhibited xylosyltransferase activity and transferred d-xylose onto l-fucose. The pectic polysaccharide rhamnogalacturonan II (RG-II), isolated from 7-day-old pollen-rescued mutant seedlings, exhibited a 30% reduction in 2-O-methyl d-xylose residues. Furthermore, an exogenous supply of boric acid enhanced RG-II dimer formation and partially restored the root growth of the pollen-rescued mutant seedlings. Taken together, these results suggest that MGP4 plays important roles in pollen tube and root growth by acting as a xylosyltransferase involved in the biosynthesis of pectic RG-II.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Pectinas/biosíntesis , Pentosiltransferasa/metabolismo , Raíces de Plantas/crecimiento & desarrollo , Tubo Polínico/crecimiento & desarrollo , Arabidopsis/enzimología , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/genética , Clonación Molecular , ADN de Plantas/genética , Regulación de la Expresión Génica de las Plantas , Prueba de Complementación Genética , Aparato de Golgi/enzimología , Mutación , Pentosiltransferasa/genética , Tubo Polínico/enzimología , Regiones Promotoras Genéticas
15.
J Integr Plant Biol ; 53(1): 74-88, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21205178

RESUMEN

In flowering plants, the exine components are derived from tapetum. Despite its importance to sexual plant reproduction, little is known about the translocation of exine materials from tapetum to developing microspores. Here we report functional characterization of the arabidopsis WBC27 gene. WBC27 encodes an adenosine tri-phosphate binding cassette (ABC) transporter and is expressed preferentially in tapetum. Mutation of WBC27 disrupted the exine formation. The wbc27 mutant microspores began to degenerate once released from tetrads and most of the microspores collapsed at the uninucleate stage. Only a small number of wbc27-1 microspores could develop into tricellular pollen grains. These survival pollen grains lacked exine and germinated in the anther before anthesis. All of these results suggest that the ABC transporter, WBC27 plays important roles in the formation of arabidopsis exine, possibly by translocation of lipidic precursors of sporopollenin from tapetum to developing microspores.


Asunto(s)
Transportadoras de Casetes de Unión a ATP/metabolismo , Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Polen/crecimiento & desarrollo , Transportador de Casetes de Unión a ATP, Subfamilia G , Transportadoras de Casetes de Unión a ATP/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Factores de Transcripción con Motivo Hélice-Asa-Hélice Básico/genética , Tipificación del Cuerpo , Membrana Celular/metabolismo , Metabolismo de los Lípidos , Mutagénesis Insercional , Fenotipo , Factores de Transcripción/genética
16.
Plant Mol Biol ; 72(1-2): 61-73, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19795213

RESUMEN

Eighteen genes that encode the proteins with highly conserved Domain of Unknown Function 724 (DUF724) and Agenet domains were identified in plant taxa but not in animals and fungi. They are actively expressed in many different plant tissues, implying that they may play important roles in plants. Here we report the characterization of their structural organizations, expression patterns and protein-protein interactions. In Arabidopsis, the DUF724 genes were expressed in roots, leaves, shoot apical meristems, anthers and pollen grains. At least seven of the ten Arabidopsis DUF724 proteins (AtDuf1 to AtDuf10) were localized in nucleus. Three of them (AtDuf3, AtDuf5 and AtDuf7) may form homodimers or homopolymers, but did not interact with other members of the same family. Together with the significant similarity between DUF724 proteins and FMRP in the fundamental and characteristic molecular architecture, the results implies the DUF724 gene family may be involved in the polar growth of plant cells via transportation of RNAs.


Asunto(s)
Proteínas de Arabidopsis/fisiología , Arabidopsis/metabolismo , Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Proteínas de Arabidopsis/clasificación , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Biología Computacional , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Filogenia , Regiones Promotoras Genéticas/genética , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Técnicas del Sistema de Dos Híbridos
17.
Plant J ; 57(5): 870-82, 2009 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-18980646

RESUMEN

In most flowering plant species, pollination and fertilization occur during the hot summer, so plants must have evolved a mechanism that ensures normal growth of their pollen tubes at high temperatures. Despite its importance to plant reproduction, little is known about the molecular basis of thermotolerance in pollen tubes. Here we report the identification and characterization of a novel Arabidopsis gene, Thermosensitive Male Sterile 1 (TMS1), which plays an important role in thermotolerance of pollen tubes. TMS1 encodes a Hsp40-homologous protein with a DnaJ domain and an a_ERdj5_C domain found in protein disulfide isomerases (PDI). Purified TMS1 expressed in Escherichia coli (BL21 DE3) had the reductive activity of PDI. TMS1 was expressed in pollen grains, pollen tubes and other vegetative tissues, including leaves, stems and roots. Heat shock treatment at 37 degrees C increased its expression levels in growing pollen tubes as well as in vegetative tissues. A knockout mutation in TMS1 grown at 30 degrees C had greatly retarded pollen tube growth in the transmitting tract, resulting in a significant reduction in male fertility. Our study suggests that TMS1 is required for thermotolerance of pollen tubes in Arabidopsis, possibly by functioning as a co-molecular chaperone.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Choque Térmico/metabolismo , Infertilidad Vegetal/genética , Tubo Polínico/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Clonación Molecular , Escherichia coli/metabolismo , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Prueba de Complementación Genética , Proteínas de Choque Térmico/genética , Respuesta al Choque Térmico/genética , Calor , Mutación , Fenotipo , Tubo Polínico/crecimiento & desarrollo , ARN de Planta/metabolismo
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