Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
1.
BMC Med Genet ; 19(1): 22, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29439679

RESUMO

BACKGROUND: Maturity-onset diabetes of the young (MODY) is an early-onset, autosomal dominant form of non-insulin dependent diabetes. Genetic diagnosis of MODY can transform patient management. Earlier data on the genetic predisposition to MODY have come primarily from familial studies in populations of European origin. METHODS: In this study, we carried out a comprehensive genomic analysis of 289 individuals from India that included 152 clinically diagnosed MODY cases to identify variants in known MODY genes. Further, we have analyzed exome data to identify putative MODY relevant variants in genes previously not implicated in MODY. Functional validation of MODY relevant variants was also performed. RESULTS: We found MODY 3 (HNF1A; 7.2%) to be most frequently mutated followed by MODY 12 (ABCC8; 3.3%). They together account for ~ 11% of the cases. In addition to known MODY genes, we report the identification of variants in RFX6, WFS1, AKT2, NKX6-1 that may contribute to development of MODY. Functional assessment of the NKX6-1 variants showed that they are functionally impaired. CONCLUSIONS: Our findings showed HNF1A and ABCC8 to be the most frequently mutated MODY genes in south India. Further we provide evidence for additional MODY relevant genes, such as NKX6-1, and these require further validation.


Assuntos
Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Diabetes Mellitus Tipo 2/genética , Predisposição Genética para Doença/epidemiologia , Adolescente , Adulto , Estudos de Coortes , Exoma , Feminino , Biblioteca Gênica , Genômica , Hemoglobinas Glicadas/metabolismo , Fator 1-alfa Nuclear de Hepatócito/genética , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Proteínas de Homeodomínio/genética , Proteínas de Homeodomínio/metabolismo , Humanos , Índia/epidemiologia , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fatores de Transcrição de Fator Regulador X/genética , Fatores de Transcrição de Fator Regulador X/metabolismo , Análise de Sequência de DNA , Receptores de Sulfonilureias/genética , Receptores de Sulfonilureias/metabolismo , Adulto Jovem
2.
Nature ; 482(7386): 495-500, 2012 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-22358839

RESUMO

Packaging of proteins from the endoplasmic reticulum into COPII vesicles is essential for secretion. In cells, most COPII vesicles are approximately 60-80 nm in diameter, yet some must increase their size to accommodate 300-400 nm procollagen fibres or chylomicrons. Impaired COPII function results in collagen deposition defects, cranio-lenticulo-sutural dysplasia, or chylomicron retention disease, but mechanisms to enlarge COPII coats have remained elusive. Here, we identified the ubiquitin ligase CUL3-KLHL12 as a regulator of COPII coat formation. CUL3-KLHL12 catalyses the monoubiquitylation of the COPII-component SEC31 and drives the assembly of large COPII coats. As a result, ubiquitylation by CUL3-KLHL12 is essential for collagen export, yet less important for the transport of small cargo. We conclude that monoubiquitylation controls the size and function of a vesicle coat.


Assuntos
Vesículas Revestidas pelo Complexo de Proteína do Envoltório/química , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Ubiquitina/metabolismo , Proteínas Adaptadoras de Transdução de Sinal , Animais , Linhagem Celular , Forma Celular , Colágeno/metabolismo , Proteínas Culina/genética , Proteínas Culina/metabolismo , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Células HeLa , Humanos , Camundongos , Proteínas dos Microfilamentos/genética , Proteínas dos Microfilamentos/metabolismo , Transporte Proteico , Ubiquitinação , Proteínas de Transporte Vesicular/genética , Proteínas de Transporte Vesicular/metabolismo
3.
BMC Genomics ; 18(1): 519, 2017 07 07.
Artigo em Inglês | MEDLINE | ID: mdl-28687070

RESUMO

BACKGROUND: Technological advances have enabled transcriptome characterization of cell types at the single-cell level providing new biological insights. New methods that enable simple yet high-throughput single-cell expression profiling are highly desirable. RESULTS: Here we report a novel nanowell-based single-cell RNA sequencing system, ICELL8, which enables processing of thousands of cells per sample. The system employs a 5,184-nanowell-containing microchip to capture ~1,300 single cells and process them. Each nanowell contains preprinted oligonucleotides encoding poly-d(T), a unique well barcode, and a unique molecular identifier. The ICELL8 system uses imaging software to identify nanowells containing viable single cells and only wells with single cells are processed into sequencing libraries. Here, we report the performance and utility of ICELL8 using samples of increasing complexity from cultured cells to mouse solid tissue samples. Our assessment of the system to discriminate between mixed human and mouse cells showed that ICELL8 has a low cell multiplet rate (< 3%) and low cross-cell contamination. We characterized single-cell transcriptomes of more than a thousand cultured human and mouse cells as well as 468 mouse pancreatic islets cells. We were able to identify distinct cell types in pancreatic islets, including alpha, beta, delta and gamma cells. CONCLUSIONS: Overall, ICELL8 provides efficient and cost-effective single-cell expression profiling of thousands of cells, allowing researchers to decipher single-cell transcriptomes within complex biological samples.


Assuntos
Perfilação da Expressão Gênica/métodos , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Nanotecnologia/métodos , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Análise Serial de Tecidos/métodos , Linhagem Celular , Humanos , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo
4.
J Biol Chem ; 287(13): 10134-10144, 2012 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-22298774

RESUMO

COPII proteins are essential for exporting most cargo molecules from the endoplasmic reticulum. The membrane-facing surface of the COPII proteins (especially SEC23-SEC24) interacts directly or indirectly with the cargo molecules destined for exit. As we characterized the SEC23A mutations at the SEC31 binding site identified from patients with cranio-lenticulo-sutural dysplasia, we discovered that the SEC23-SEC31 interface can also influence cargo selection. Remarkably, M702V SEC23A does not compromise COPII assembly, vesicle size, and packaging of cargo molecules into COPII vesicles that we have tested but induces accumulation of procollagen in the endoplasmic reticulum when expressed in normal fibroblasts. We observed that M702V SEC23A activates SAR1B GTPase more than wild-type SEC23A when SEC13-SEC31 is present, indicating that M702V SEC23A causes premature dissociation of COPII from the membrane. Our results indicate that a longer stay of COPII proteins on the membrane is required to cargo procollagen than other molecules and suggest that the SEC23-SEC31 interface plays a critical role in capturing various cargo molecules.


Assuntos
Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Retículo Endoplasmático/metabolismo , Pró-Colágeno/metabolismo , Proteínas de Transporte Vesicular/metabolismo , Substituição de Aminoácidos , Animais , Vesículas Revestidas pelo Complexo de Proteína do Envoltório/genética , Linhagem Celular Tumoral , Retículo Endoplasmático/genética , Humanos , Mutação de Sentido Incorreto , Pró-Colágeno/genética , Ligação Proteica , Transporte Proteico/fisiologia , Ratos , Proteínas de Transporte Vesicular/genética
5.
Curr Protoc ; 3(9): e872, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37671955

RESUMO

The drug discovery landscape is ever-evolving and constantly demands revolutionary technology advancements in protein expression and production laboratories. We have built a higher-throughput mid-scale semi-automated protein expression and screening platform to accelerate drug discovery research. The workflow described here enables comprehensive expression and purification screening assessment of challenging or difficult-to-express recombinant proteins in a fast and efficient manner by delivering small but sufficient amounts of high-quality proteins. The platform has been implemented for a wide range of applications that include identification of optimal constructs and chaperones for poorly expressing proteins, assessment of co-expression partners for expressing stable multiprotein complexes, and suitable buffer/additive screening for insoluble or aggregation-prone proteins. The approach allows parallel expression, purification, and characterization of 24 different samples using co-infection or a polycistronic approach in insect cells and enables parallel testing of multiple parameters to improve protein yields. The strategy has been successfully adopted for screening intracellular and secreted proteins in Escherichia coli, mammalian transient expression, and baculovirus expression vector systems. Proteins purified from this platform are used for several structural and functional screens, such as negative staining, biochemical activity assays, mass spectrometry, surface plasmon resonance, and DNA-encoded chemical library screens. In this article, for simplicity, we have focused on detailed expression and purification screening of intracellular protein complexes from insect cells. © 2023 Wiley Periodicals LLC. Basic Protocol 1: Baculovirus generation via homologous recombination Support Protocol 1: Anti-glycoprotein 64 antibody assay Basic Protocol 2: Generation of insect cell biomass expressing target protein(s) Basic Protocol 3: Mid-scale affinity purification Support Protocol 2: Automated method for affinity purification on Hamilton STAR Basic Protocol 4: Size exclusion chromatography Support Protocol 3: Chromeleon 7 operation on Vanquish Duo.


Assuntos
Acetaminofen , Aspirina , Animais , Baculoviridae , Bioensaio , Descoberta de Drogas , Escherichia coli , Mamíferos
6.
Commun Biol ; 2: 304, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428692

RESUMO

Obtaining full-length antibody heavy- and light-chain variable regions from individual B cells at scale remains a challenging problem. Here we use high-throughput single-cell B-cell receptor sequencing (scBCR-seq) to obtain accurately paired full-length variable regions in a massively parallel fashion. We sequenced more than 250,000 B cells from rat, mouse and human repertoires to characterize their lineages and expansion. In addition, we immunized rats with chicken ovalbumin and profiled antigen-reactive B cells from lymph nodes of immunized animals. The scBCR-seq data recovered 81% (n = 56/69) of B-cell lineages identified from hybridomas generated from the same set of B cells subjected to scBCR-seq. Importantly, scBCR-seq identified an additional 710 candidate lineages not recovered as hybridomas. We synthesized, expressed and tested 93 clones from the identified lineages and found that 99% (n = 92/93) of the clones were antigen-reactive. Our results establish scBCR-seq as a powerful tool for antibody discovery.


Assuntos
Anticorpos/metabolismo , Antígenos/metabolismo , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Receptores de Antígenos de Linfócitos B/genética , Análise de Célula Única , Animais , Células Germinativas/metabolismo , Humanos , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Leves de Imunoglobulina/genética , Camundongos , Ratos , Reprodutibilidade dos Testes
7.
Cancer Cell ; 34(5): 792-806.e5, 2018 11 12.
Artigo em Inglês | MEDLINE | ID: mdl-30449325

RESUMO

Deregulated HER2 is a target of many approved cancer drugs. We analyzed 111,176 patient tumors and identified recurrent mutations in HER2 transmembrane domain (TMD) and juxtamembrane domain (JMD) that include G660D, R678Q, E693K, and Q709L. Using a saturation mutagenesis screen and testing of patient-derived mutations we found several activating TMD and JMD mutations. Structural modeling and analysis showed that the TMD/JMD mutations function by improving the active dimer interface or stabilizing an activating conformation. Further, we found that HER2 G660D employed asymmetric kinase dimerization for activation and signaling. Importantly, anti-HER2 antibodies and small-molecule kinase inhibitors blocked the activity of TMD/JMD mutants. Consistent with this, a G660D germline mutant lung cancer patient showed remarkable clinical response to HER2 blockade.


Assuntos
Neoplasias Pulmonares/genética , Domínios Proteicos/genética , Receptor ErbB-2/genética , Receptor ErbB-2/metabolismo , Adulto , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Feminino , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Simulação de Dinâmica Molecular , Mutação/genética , Conformação Proteica , Inibidores de Proteínas Quinases/farmacologia , Receptor ErbB-2/antagonistas & inibidores , Transdução de Sinais
8.
Nat Genet ; 47(1): 13-21, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25401301

RESUMO

To further understand the molecular distinctions between kidney cancer subtypes, we analyzed exome, transcriptome and copy number alteration data from 167 primary human tumors that included renal oncocytomas and non-clear cell renal cell carcinomas (nccRCCs), consisting of papillary (pRCC), chromophobe (chRCC) and translocation (tRCC) subtypes. We identified ten significantly mutated genes in pRCC, including MET, NF2, SLC5A3, PNKD and CPQ. MET mutations occurred in 15% (10/65) of pRCC samples and included previously unreported recurrent activating mutations. In chRCC, we found TP53, PTEN, FAAH2, PDHB, PDXDC1 and ZNF765 to be significantly mutated. Gene expression analysis identified a five-gene set that enabled the molecular classification of chRCC, renal oncocytoma and pRCC. Using RNA sequencing, we identified previously unreported gene fusions, including ACTG1-MITF fusion. Ectopic expression of the ACTG1-MITF fusion led to cellular transformation and induced the expression of downstream target genes. Finally, we observed upregulation of the anti-apoptotic factor BIRC7 in MiTF-high RCC tumors, suggesting a potential therapeutic role for BIRC7 inhibitors.


Assuntos
Carcinoma de Células Renais/classificação , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Neoplasias Renais/genética , Mutação , Adenoma Oxífilo/classificação , Adenoma Oxífilo/genética , Adenoma Oxífilo/patologia , Sequência de Aminoácidos , Sequência de Bases , Biomarcadores Tumorais/genética , Carcinoma de Células Renais/genética , Carcinoma de Células Renais/patologia , DNA de Neoplasias , Dosagem de Genes , Instabilidade Genômica , Humanos , Neoplasias Renais/classificação , Neoplasias Renais/patologia , Dados de Sequência Molecular , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/fisiologia , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/fisiologia , Polimorfismo de Nucleotídeo Único , Conformação Proteica , Proteínas Proto-Oncogênicas c-met/química , Proteínas Proto-Oncogênicas c-met/genética , Translocação Genética
9.
Nat Cell Biol ; 14(1): 20-8, 2011 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-22193160

RESUMO

Secretory proteins are transported to the Golgi complex in vesicles that bud from the endoplasmic reticulum. The cytoplasmic coat protein complex II (COPII) is responsible for cargo sorting and vesicle morphogenesis. COPII was first described in Saccharomyces cerevisiae, but its basic function is conserved throughout all eukaryotes. Nevertheless, the COPII coat has adapted to the higher complexity of mammalian physiology, achieving more sophisticated levels of secretory regulation. In this review we cover aspects of mammalian COPII-mediated regulation of secretion, in particular related to the function of COPII paralogues, the spatial organization of cargo export and the role of accessory proteins.


Assuntos
Vesículas Revestidas pelo Complexo de Proteína do Envoltório/metabolismo , Retículo Endoplasmático/metabolismo , Complexo de Golgi/metabolismo , Via Secretória/fisiologia , Animais , Humanos , Mamíferos , Transporte Proteico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA