RESUMO
The peroxisome proliferator-activated receptor γ coactivator-1α (Ppargc1a) gene encodes several PGC-1α isoforms that regulate mitochondrial bioenergetics and cellular adaptive processes. Expressing specific PGC-1α isoforms in mice can confer protection in different disease models. This SnapShot summarizes how regulation of Ppargc1a transcription, splicing, translation, protein stability, and activity underlies its multifaceted functions. To view this SnapShot, open or download the PDF.
Assuntos
Regulação da Expressão Gênica , Mitocôndrias , Animais , Biologia , Metabolismo Energético , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/genética , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismoRESUMO
Retrotransposons mediate gene regulation in important developmental and pathological processes. Here, we characterized the transient retrotransposon induction during preimplantation development of eight mammals. Induced retrotransposons exhibit similar preimplantation profiles across species, conferring gene regulatory activities, particularly through long terminal repeat (LTR) retrotransposon promoters. A mouse-specific MT2B2 retrotransposon promoter generates an N-terminally truncated Cdk2ap1ΔN that peaks in preimplantation embryos and promotes proliferation. In contrast, the canonical Cdk2ap1 peaks in mid-gestation and represses cell proliferation. This MT2B2 promoter, whose deletion abolishes Cdk2ap1ΔN production, reduces cell proliferation and impairs embryo implantation, is developmentally essential. Intriguingly, Cdk2ap1ΔN is evolutionarily conserved in sequence and function yet is driven by different promoters across mammals. The distinct preimplantation Cdk2ap1ΔN expression in each mammalian species correlates with the duration of its preimplantation development. Hence, species-specific transposon promoters can yield evolutionarily conserved, alternative protein isoforms, bestowing them with new functions and species-specific expression to govern essential biological divergence.
Assuntos
Sequência Conservada , Desenvolvimento Embrionário/genética , Proteínas Quinases/metabolismo , Retroelementos/genética , Proteínas Supressoras de Tumor/metabolismo , Animais , Sequência de Bases , Blastocisto/metabolismo , Proliferação de Células , Evolução Molecular , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Células-Tronco Embrionárias Humanas/metabolismo , Humanos , Mamíferos/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Modelos Biológicos , Regiões Promotoras Genéticas , Isoformas de Proteínas/metabolismoRESUMO
Many organisms evolved strategies to survive desiccation. Plant seeds protect dehydrated embryos from various stressors and can lay dormant for millennia. Hydration is the key trigger to initiate germination, but the mechanism by which seeds sense water remains unresolved. We identified an uncharacterized Arabidopsis thaliana prion-like protein we named FLOE1, which phase separates upon hydration and allows the embryo to sense water stress. We demonstrate that biophysical states of FLOE1 condensates modulate its biological function in vivo in suppressing seed germination under unfavorable environments. We find intragenic, intraspecific, and interspecific natural variation in FLOE1 expression and phase separation and show that intragenic variation is associated with adaptive germination strategies in natural populations. This combination of molecular, organismal, and ecological studies uncovers FLOE1 as a tunable environmental sensor with direct implications for the design of drought-resistant crops, in the face of climate change.
Assuntos
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Germinação , Peptídeos e Proteínas de Sinalização Intercelular/metabolismo , Príons/metabolismo , Sementes/crescimento & desenvolvimento , Água/metabolismo , Arabidopsis/genética , Arabidopsis/ultraestrutura , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/ultraestrutura , Desidratação , Imageamento Tridimensional , Peptídeos e Proteínas de Sinalização Intercelular/química , Mutação/genética , Dormência de Plantas , Plantas Geneticamente Modificadas , Domínios Proteicos , Isoformas de Proteínas/metabolismo , Sementes/ultraestruturaRESUMO
Cancer cell genetic variability and similarity to host cells have stymied development of broad anti-cancer therapeutics. Our innate immune system evolved to clear genetically diverse pathogens and limit host toxicity; however, whether/how innate immunity can produce similar effects in cancer is unknown. Here, we show that human, but not murine, neutrophils release catalytically active neutrophil elastase (ELANE) to kill many cancer cell types while sparing non-cancer cells. ELANE proteolytically liberates the CD95 death domain, which interacts with histone H1 isoforms to selectively eradicate cancer cells. ELANE attenuates primary tumor growth and produces a CD8+T cell-mediated abscopal effect to attack distant metastases. Porcine pancreatic elastase (ELANE homolog) resists tumor-derived protease inhibitors and exhibits markedly improved therapeutic efficacy. Altogether, our studies suggest that ELANE kills genetically diverse cancer cells with minimal toxicity to non-cancer cells, raising the possibility of developing it as a broad anti-cancer therapy.
Assuntos
Carcinogênese/patologia , Elastase de Leucócito/metabolismo , Neoplasias/enzimologia , Neoplasias/patologia , Regulação Alostérica/efeitos dos fármacos , Animais , Linfócitos T CD8-Positivos/imunologia , Carcinogênese/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proteína Catiônica de Eosinófilo/metabolismo , Histonas/metabolismo , Humanos , Camundongos , Neoplasias/imunologia , Neutrófilos/efeitos dos fármacos , Neutrófilos/enzimologia , Elastase Pancreática/metabolismo , Inibidores de Proteases/farmacologia , Domínios Proteicos , Isoformas de Proteínas/metabolismo , Proteólise/efeitos dos fármacos , Inibidor Secretado de Peptidases Leucocitárias/metabolismo , Suínos , Receptor fas/química , Receptor fas/metabolismoRESUMO
Although mutations in DNA are the best-studied source of neoantigens that determine response to immune checkpoint blockade, alterations in RNA splicing within cancer cells could similarly result in neoepitope production. However, the endogenous antigenicity and clinical potential of such splicing-derived epitopes have not been tested. Here, we demonstrate that pharmacologic modulation of splicing via specific drug classes generates bona fide neoantigens and elicits anti-tumor immunity, augmenting checkpoint immunotherapy. Splicing modulation inhibited tumor growth and enhanced checkpoint blockade in a manner dependent on host T cells and peptides presented on tumor MHC class I. Splicing modulation induced stereotyped splicing changes across tumor types, altering the MHC I-bound immunopeptidome to yield splicing-derived neoepitopes that trigger an anti-tumor T cell response in vivo. These data definitively identify splicing modulation as an untapped source of immunogenic peptides and provide a means to enhance response to checkpoint blockade that is readily translatable to the clinic.
Assuntos
Neoplasias/genética , Neoplasias/imunologia , Splicing de RNA/genética , Animais , Apresentação de Antígeno/efeitos dos fármacos , Apresentação de Antígeno/imunologia , Antígenos de Neoplasias/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Epitopos/imunologia , Etilenodiaminas/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Hematopoese/efeitos dos fármacos , Hematopoese/genética , Antígenos de Histocompatibilidade Classe I/metabolismo , Humanos , Inibidores de Checkpoint Imunológico/farmacologia , Imunoterapia , Inflamação/patologia , Camundongos Endogâmicos C57BL , Peptídeos/metabolismo , Isoformas de Proteínas/metabolismo , Pirróis/farmacologia , Splicing de RNA/efeitos dos fármacos , Sulfonamidas/farmacologia , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologiaRESUMO
The evolution of eukaryotic genomes has been propelled by a series of gene duplication events, leading to an expansion in new functions and pathways. While duplicate genes may retain some functional redundancy, it is clear that to survive selection they cannot simply serve as a backup but rather must acquire distinct functions required for cellular processes to work accurately and efficiently. Understanding these differences and characterizing gene-specific functions is complex. Here we explore different gene pairs and families within the context of the endoplasmic reticulum (ER), the main cellular hub of lipid biosynthesis and the entry site for the secretory pathway. Focusing on each of the ER functions, we highlight specificities of related proteins and the capabilities conferred to cells through their conservation. More generally, these examples suggest why related genes have been maintained by evolutionary forces and provide a conceptual framework to experimentally determine why they have survived selection.
Assuntos
Retículo Endoplasmático/metabolismo , Evolução Molecular , Duplicação Gênica , Saccharomyces cerevisiae/metabolismo , Seleção Genética , Fator 6 Ativador da Transcrição/genética , Fator 6 Ativador da Transcrição/metabolismo , Animais , Antiporters/genética , Antiporters/metabolismo , Carboxiliases/genética , Carboxiliases/metabolismo , Retículo Endoplasmático/genética , Endorribonucleases/genética , Endorribonucleases/metabolismo , Células Eucarióticas/citologia , Células Eucarióticas/metabolismo , Proteínas de Choque Térmico HSP40/genética , Proteínas de Choque Térmico HSP40/metabolismo , Hexosiltransferases/genética , Hexosiltransferases/metabolismo , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Esfingosina N-Aciltransferase/genética , Esfingosina N-Aciltransferase/metabolismo , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismoRESUMO
To elucidate the role of Tau isoforms and post-translational modification (PTM) stoichiometry in Alzheimer's disease (AD), we generated a high-resolution quantitative proteomics map of 95 PTMs on multiple isoforms of Tau isolated from postmortem human tissue from 49 AD and 42 control subjects. Although Tau PTM maps reveal heterogeneity across subjects, a subset of PTMs display high occupancy and frequency for AD, suggesting importance in disease. Unsupervised analyses indicate that PTMs occur in an ordered manner, leading to Tau aggregation. The processive addition and minimal set of PTMs associated with seeding activity was further defined by analysis of size-fractionated Tau. To summarize, features in the Tau protein critical for disease intervention at different stages of disease are identified, including enrichment of 0N and 4R isoforms, underrepresentation of the C terminus, an increase in negative charge in the proline-rich region (PRR), and a decrease in positive charge in the microtubule binding domain (MBD).
Assuntos
Doença de Alzheimer/metabolismo , Doença de Alzheimer/patologia , Processamento de Proteína Pós-Traducional , Proteínas tau/metabolismo , Estudos de Casos e Controles , Estudos de Coortes , Progressão da Doença , Humanos , Análise de Componente Principal , Isoformas de Proteínas/metabolismoRESUMO
Problems arising during translation of mRNAs lead to ribosome stalling and collisions that trigger a series of quality control events. However, the global cellular response to ribosome collisions has not been explored. Here, we uncover a function for ribosome collisions in signal transduction. Using translation elongation inhibitors and general cellular stress conditions, including amino acid starvation and UV irradiation, we show that ribosome collisions activate the stress-activated protein kinase (SAPK) and GCN2-mediated stress response pathways. We show that the MAPKKK ZAK functions as the sentinel for ribosome collisions and is required for immediate early activation of both SAPK (p38/JNK) and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that although ZAK generally associates with elongating ribosomes on polysomal mRNAs, it specifically auto-phosphorylates on the minimal unit of colliding ribosomes, the disome. Together, these results provide molecular insights into how perturbation of translational homeostasis regulates cell fate.
Assuntos
Ribossomos/metabolismo , Estresse Fisiológico , Transportadores de Cassetes de Ligação de ATP/metabolismo , Anisomicina/farmacologia , Apoptose/efeitos dos fármacos , Dano ao DNA/efeitos da radiação , Ativação Enzimática , Humanos , MAP Quinase Quinase Quinases/deficiência , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Proteína Quinase 14 Ativada por Mitógeno/antagonistas & inibidores , Proteína Quinase 14 Ativada por Mitógeno/metabolismo , Fosforilação , Polirribossomos/metabolismo , Isoformas de Proteínas/deficiência , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/metabolismo , Transdução de Sinais , Raios Ultravioleta , eIF-2 Quinase/metabolismoRESUMO
ß-arrestins (ßarrs) play multifaceted roles in the signaling and regulation of G-protein-coupled receptors (GPCRs) including their desensitization and endocytosis. Recently determined cryo-EM structures of two different GPCRs in complex with ßarr1 provide the first glimpse of GPCR-ßarr engagement and a structural framework to understand their interaction.
Assuntos
Receptores Acoplados a Proteínas G/ultraestrutura , beta-Arrestinas/metabolismo , beta-Arrestinas/ultraestrutura , Arrestinas/metabolismo , Endocitose/fisiologia , Proteínas de Ligação ao GTP/metabolismo , Humanos , Fosforilação , Ligação Proteica , Isoformas de Proteínas/ultraestrutura , Receptores Acoplados a Proteínas G/metabolismo , Transdução de Sinais/fisiologia , Relação Estrutura-Atividade , beta-Arrestina 1/metabolismo , beta-Arrestina 2/metabolismoRESUMO
Muscle spasticity after nervous system injuries and painful low back spasm affect more than 10% of global population. Current medications are of limited efficacy and cause neurological and cardiovascular side effects because they target upstream regulators of muscle contraction. Direct myosin inhibition could provide optimal muscle relaxation; however, targeting skeletal myosin is particularly challenging because of its similarity to the cardiac isoform. We identified a key residue difference between these myosin isoforms, located in the communication center of the functional regions, which allowed us to design a selective inhibitor, MPH-220. Mutagenic analysis and the atomic structure of MPH-220-bound skeletal muscle myosin confirmed the mechanism of specificity. Targeting skeletal muscle myosin by MPH-220 enabled muscle relaxation, in human and model systems, without cardiovascular side effects and improved spastic gait disorders after brain injury in a disease model. MPH-220 provides a potential nervous-system-independent option to treat spasticity and muscle stiffness.
Assuntos
Músculo Esquelético/metabolismo , Miosinas de Músculo Esquelético/efeitos dos fármacos , Miosinas de Músculo Esquelético/genética , Adulto , Animais , Miosinas Cardíacas/genética , Miosinas Cardíacas/metabolismo , Linhagem Celular , Sistemas de Liberação de Medicamentos , Feminino , Humanos , Masculino , Camundongos , Contração Muscular/fisiologia , Fibras Musculares Esqueléticas/fisiologia , Espasticidade Muscular/genética , Espasticidade Muscular/fisiopatologia , Músculo Esquelético/fisiologia , Miosinas/efeitos dos fármacos , Miosinas/genética , Miosinas/metabolismo , Isoformas de Proteínas , Ratos , Ratos Wistar , Miosinas de Músculo Esquelético/metabolismoRESUMO
A developmental program affecting human face shape is shown by Greenberg et al. (2019) to hinge on the ability to distinguish a single methyl group between two histone variant isoforms and the action of the chromatin-remodeling enzyme SRCAP. This challenges researchers to link atomic structure to a morphological defect.
Assuntos
Cromatina , Histonas , Aminoácidos , Montagem e Desmontagem da Cromatina , Humanos , Isoformas de ProteínasRESUMO
Understanding transcription factor navigation through the nucleus remains critical for developing targeted therapeutics. The GLI1 transcription factor must maintain maximal Hedgehog pathway output in basal cell carcinomas (BCCs), and we have previously shown that resistant BCCs increase GLI1 deacetylation through atypical protein kinase Cι/λ (aPKC) and HDAC1. Here we identify a lamina-associated polypeptide 2 (LAP2) isoform-dependent nuclear chaperoning system that regulates GLI1 movement between the nuclear lamina and nucleoplasm to achieve maximal activation. LAP2ß forms a two-site interaction with the GLI1 zinc-finger domain and acetylation site, stabilizing an acetylation-dependent reserve on the inner nuclear membrane (INM). By contrast, the nucleoplasmic LAP2α competes with LAP2ß for GLI1 while scaffolding HDAC1 to deacetylate the secondary binding site. aPKC functions to promote GLI1 association with LAP2α, promoting egress off the INM. GLI1 intranuclear trafficking by LAP2 isoforms represents a powerful signal amplifier in BCCs with implications for zinc finger-based signal transduction and therapeutics.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Proteínas de Membrana/metabolismo , Proteína GLI1 em Dedos de Zinco/metabolismo , Células 3T3 , Animais , Carcinoma Basocelular/metabolismo , Linhagem Celular , Cromatina , Proteínas de Ligação a DNA/fisiologia , Células HEK293 , Proteínas Hedgehog/metabolismo , Proteínas Hedgehog/fisiologia , Histona Desacetilase 1/metabolismo , Humanos , Proteínas de Membrana/fisiologia , Camundongos , Chaperonas Moleculares/metabolismo , Lâmina Nuclear/metabolismo , Proteínas Nucleares/metabolismo , Isoformas de Proteínas/metabolismo , Transdução de Sinais , Transativadores/metabolismo , Fatores de Transcrição/metabolismo , Proteína GLI1 em Dedos de Zinco/fisiologia , Dedos de ZincoRESUMO
The single most frequent cancer-causing mutation across all heterotrimeric G proteins is R201C in Gαs. The current model explaining the gain-of-function activity of the R201 mutations is through the loss of GTPase activity and resulting inability to switch off to the GDP state. Here, we find that the R201C mutation can bypass the need for GTP binding by directly activating GDP-bound Gαs through stabilization of an intramolecular hydrogen bond network. Having found that a gain-of-function mutation can convert GDP into an activator, we postulated that a reciprocal mutation might disrupt the normal role of GTP. Indeed, we found R228C, a loss-of-function mutation in Gαs that causes pseudohypoparathyroidism type 1a (PHP-Ia), compromised the adenylyl cyclase-activating activity of Gαs bound to a non-hydrolyzable GTP analog. These findings show that disease-causing mutations in Gαs can subvert the canonical roles of GDP and GTP, providing new insights into the regulation mechanism of G proteins.
Assuntos
Subunidades alfa Gs de Proteínas de Ligação ao GTP/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Adenilil Ciclases/química , Adenilil Ciclases/metabolismo , Cristalografia por Raios X , Subunidades alfa Gs de Proteínas de Ligação ao GTP/química , Subunidades alfa Gs de Proteínas de Ligação ao GTP/genética , Humanos , Ligação de Hidrogênio , Mutagênese Sítio-Dirigida , Ligação Proteica , Isoformas de Proteínas/química , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Estrutura Terciária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificaçãoRESUMO
Dicer proteins are known to produce small RNAs (sRNAs) from long double-stranded RNA (dsRNA) templates. These sRNAs are bound by Argonaute proteins, which select the guide strand, often with a 5' end sequence bias. However, Dicer proteins have never been shown to have sequence cleavage preferences. In Paramecium development, two classes of sRNAs that are required for DNA elimination are produced by three Dicer-like enzymes: Dcl2, Dcl3, and Dcl5. Through in vitro cleavage assays, we demonstrate that Dcl2 has a strict size preference for 25 nt and a sequence preference for 5' U and 5' AGA, while Dcl3 has a sequence preference for 5' UNG. Dcl5, however, has cleavage preferences for 5' UAG and 3' CUAC/UN, which leads to the production of RNAs precisely matching short excised DNA elements with corresponding end base preferences. Thus, we characterize three Dicer-like enzymes that are involved in Paramecium development and propose a biological role for their sequence-biased cleavage products.
Assuntos
Paramecium/genética , Proteínas de Protozoários/metabolismo , Ribonuclease III/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Elementos de DNA Transponíveis/genética , Paramecium/metabolismo , Filogenia , Isoformas de Proteínas/classificação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas de Protozoários/classificação , Proteínas de Protozoários/genética , Clivagem do RNA , RNA de Cadeia Dupla/metabolismo , RNA Interferente Pequeno/química , RNA Interferente Pequeno/metabolismo , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Ribonuclease III/classificação , Ribonuclease III/genética , Alinhamento de Sequência , Análise de Sequência de RNARESUMO
To better understand the gene regulatory mechanisms that program developmental processes, we carried out simultaneous genome-wide measurements of mRNA, translation, and protein through meiotic differentiation in budding yeast. Surprisingly, we observed that the levels of several hundred mRNAs are anti-correlated with their corresponding protein products. We show that rather than arising from canonical forms of gene regulatory control, the regulation of at least 380 such cases, or over 8% of all measured genes, involves temporally regulated switching between production of a canonical, translatable transcript and a 5' extended isoform that is not efficiently translated into protein. By this pervasive mechanism for the modulation of protein levels through a natural developmental program, a single transcription factor can coordinately activate and repress protein synthesis for distinct sets of genes. The distinction is not based on whether or not an mRNA is induced but rather on the type of transcript produced.
Assuntos
Meiose/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Modelos Biológicos , Anotação de Sequência Molecular , Biossíntese de Proteínas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteoma/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Reprodutibilidade dos Testes , Saccharomyces cerevisiae/citologia , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/metabolismoRESUMO
Fetal hemoglobin (HbF, α2γ2) level is genetically controlled and modifies severity of adult hemoglobin (HbA, α2ß2) disorders, sickle cell disease, and ß-thalassemia. Common genetic variation affects expression of BCL11A, a regulator of HbF silencing. To uncover how BCL11A supports the developmental switch from γ- to ß- globin, we use a functional assay and protein binding microarray to establish a requirement for a zinc-finger cluster in BCL11A in repression and identify a preferred DNA recognition sequence. This motif appears in embryonic and fetal-expressed globin promoters and is duplicated in γ-globin promoters. The more distal of the duplicated motifs is mutated in individuals with hereditary persistence of HbF. Using the CUT&RUN approach to map protein binding sites in erythroid cells, we demonstrate BCL11A occupancy preferentially at the distal motif, which can be disrupted by editing the promoter. Our findings reveal that direct γ-globin gene promoter repression by BCL11A underlies hemoglobin switching.
Assuntos
Proteínas de Transporte/metabolismo , Hemoglobina Fetal/genética , Proteínas Nucleares/metabolismo , Sequência de Bases , Sítios de Ligação , Proteínas de Transporte/genética , Linhagem Celular , Cromatina/metabolismo , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas/genética , Células Eritroides/citologia , Células Eritroides/metabolismo , Edição de Genes , Humanos , Proteínas Nucleares/genética , Regiões Promotoras Genéticas , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteínas Repressoras , Dedos de Zinco/genética , Globinas beta/genética , Talassemia beta/genética , Talassemia beta/patologia , gama-Globinas/genéticaRESUMO
Chronic social isolation causes severe psychological effects in humans, but their neural bases remain poorly understood. 2 weeks (but not 24 hr) of social isolation stress (SIS) caused multiple behavioral changes in mice and induced brain-wide upregulation of the neuropeptide tachykinin 2 (Tac2)/neurokinin B (NkB). Systemic administration of an Nk3R antagonist prevented virtually all of the behavioral effects of chronic SIS. Conversely, enhancing NkB expression and release phenocopied SIS in group-housed mice, promoting aggression and converting stimulus-locked defensive behaviors to persistent responses. Multiplexed analysis of Tac2/NkB function in multiple brain areas revealed dissociable, region-specific requirements for both the peptide and its receptor in different SIS-induced behavioral changes. Thus, Tac2 coordinates a pleiotropic brain state caused by SIS via a distributed mode of action. These data reveal the profound effects of prolonged social isolation on brain chemistry and function and suggest potential new therapeutic applications for Nk3R antagonists.
Assuntos
Encéfalo/metabolismo , Neurocinina B/metabolismo , Precursores de Proteínas/metabolismo , Isolamento Social , Estresse Psicológico , Taquicininas/metabolismo , Animais , Antipsicóticos/farmacologia , Comportamento Animal/efeitos dos fármacos , Encéfalo/patologia , Feminino , Vetores Genéticos/administração & dosagem , Vetores Genéticos/genética , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Neurocinina B/genética , Neurônios/citologia , Neurônios/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Precursores de Proteínas/antagonistas & inibidores , Precursores de Proteínas/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Receptores de Taquicininas/antagonistas & inibidores , Receptores de Taquicininas/metabolismo , Taquicininas/antagonistas & inibidores , Taquicininas/genética , Regulação para Cima/efeitos dos fármacosRESUMO
Coexpression of proteins in response to pathway-inducing signals is the founding paradigm of gene regulation. However, it remains unexplored whether the relative abundance of co-regulated proteins requires precise tuning. Here, we present large-scale analyses of protein stoichiometry and corresponding regulatory strategies for 21 pathways and 67-224 operons in divergent bacteria separated by 0.6-2 billion years. Using end-enriched RNA-sequencing (Rend-seq) with single-nucleotide resolution, we found that many bacterial gene clusters encoding conserved pathways have undergone massive divergence in transcript abundance and architectures via remodeling of internal promoters and terminators. Remarkably, these evolutionary changes are compensated post-transcriptionally to maintain preferred stoichiometry of protein synthesis rates. Even more strikingly, in eukaryotic budding yeast, functionally analogous proteins that arose independently from bacterial counterparts also evolved to convergent in-pathway expression. The broad requirement for exact protein stoichiometries despite regulatory divergence provides an unexpected principle for building biological pathways both in nature and for synthetic activities.
Assuntos
Enzimas/química , Escherichia coli/enzimologia , Evolução Molecular , Isoformas de Proteínas/química , Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Escherichia coli/genética , Regulação Bacteriana da Expressão Gênica , Humanos , Família Multigênica , Óperon , Filogenia , Regiões Promotoras Genéticas , RNA Mensageiro/metabolismo , Ribossomos/química , Análise de Sequência de RNA , TranscriptomaRESUMO
The ability of living systems to adapt to changing conditions originates from their capacity to change their molecular constitution. This is achieved by multiple mechanisms that modulate the quantitative composition and the diversity of the molecular inventory. Molecular diversification is particularly pronounced on the proteome level, at which multiple proteoforms derived from the same gene can in turn combinatorially form different protein complexes, thus expanding the repertoire of functional modules in the cell. The study of molecular and modular diversity and their involvement in responses to changing conditions has only recently become possible through the development of new 'omics'-based screening technologies. This Review explores our current knowledge of the mechanisms regulating functional diversification along the axis of gene expression, with a focus on the proteome and interactome. We explore the interdependence between different molecular levels and how this contributes to functional diversity. Finally, we highlight several recent techniques for studying molecular diversity, with specific focus on mass spectrometry-based analysis of the proteome and its organization into functional modules, and examine future directions for this rapidly growing field.
Assuntos
Proteoma/química , Proteoma/metabolismo , Proteômica , Animais , Redes Reguladoras de Genes , Humanos , Complexos Multiproteicos , Mapas de Interação de Proteínas , Isoformas de Proteínas , Proteínas/química , Proteínas/genética , Proteínas/metabolismo , Proteoma/genética , TranscriptomaRESUMO
Microtubules are core components of the eukaryotic cytoskeleton with essential roles in cell division, shaping, motility and intracellular transport. Despite their functional heterogeneity, microtubules have a highly conserved structure made from almost identical molecular building blocks: the tubulin proteins. Alternative tubulin isotypes and a variety of post-translational modifications control the properties and functions of the microtubule cytoskeleton, a concept known as the 'tubulin code'. Here we review the current understanding of the molecular components of the tubulin code and how they impact microtubule properties and functions. We discuss how tubulin isotypes and post-translational modifications control microtubule behaviour at the molecular level and how this translates into physiological functions at the cellular and organism levels. We then go on to show how fine-tuning of microtubule function by some tubulin modifications can affect homeostasis and how perturbation of this fine-tuning can lead to a range of dysfunctions, many of which are linked to human disease.