Navegando por Palavras-chave "kinase"

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    In vivo and in vitro phosphorylation and subcellular localization of trypanosomatid cytoskeletal giant proteins
    (Wiley-Blackwell, 2000-09-01) Baqui, MMA; Milder, R.; Mortara, Renato Arruda [UNIFESP]; Pudles, J.; Universidade de São Paulo (USP); Universidade Federal de São Paulo (UNIFESP)
    Promastigote forms of Phytomonas serpens, Leptomonas samueli, and Leishmania tarentolae express cytoskeletal giant proteins with apparent molecular masses of 3,500 kDa (Ps 3500), 2,500 kDa (Ls 2500), and 1,200 kDa (Lt 1200). respectively. Polyclonal antibodies to it 1200 and to Ps 3500 specifically recognize similar polypeptides of the same genera of parasite. in addition to reacting with giant polypeptides of the Leptomonas species, anti-is 2500 also cross reacts with Ps 3500, and with a 500-kDa polypeptide of Leishmania. Confocal immunofluorescence and immunogold electron microscopy showed major differences in topological distribution of these three proteins, though they partially share a common localization at the anterior end of the cell body skeleton. Furthermore, Ps 3500. Ls 2500, and it 1200 are in vivo phosphorylated at serine and threonine residues, whereas, in vitro phosphorylation of cytoskeletal fractions reveal that only Ps 3500 and Ls 2500 are phosphorylated. Heat treatment (100 degrees C) of high salt cytoskeletal extracts demonstrates that Ps 3500 and Ls 2500 remain stable in solution, whereas it 1200 is denatured. Kinase assays with immunocomplexes of heat-treated giant proteins show that only Ps 3500 and Ls 2500 are phosphorylated. These results demonstrate the existence of a novel class of megadalton phosphoproteins in promastigote forms of trypanosomatids that appear to be genera specific with distinct cytoskeletal functions. in addition, there is also evidence that Ps 3500 and is 2500, in contrast to it 1200, seem to be autophosphorylating serine and threonine protein kinases, suggesting that they might play regulatory roles in the cytoskeletal organization. (C) 2000 Wiley-Liss, Inc.
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    Search for mutations in signaling pathways in head and neck squamous cell carcinoma
    (Spandidos Publ Ltd, 2013-07-01) Carvalho, Thais Gulim de [UNIFESP]; Carvalho, Ana Carolina de [UNIFESP]; Maia, Danielle Calheiros Campelo [UNIFESP]; Ogawa, Juliana Kaori [UNIFESP]; Carvalho, Andre Lopes; Vettore, Andre Luiz [UNIFESP]; Universidade Federal de São Paulo (UNIFESP); Barretos Canc Hosp
    Mutations in JAK-STAT signaling pathway genes have been associated with the development of various hematological tumors, but have not been investigated in head and neck tumors, and the PIK3CA, BRAF and KRAS genes have been described in a few cases of head and neck squamous cell carcinoma (HNSCC). in the present study, we determined the mutation status in members of the MAPK, PI3K-AKT and JAK-STAT pathways in HNSCC. Mutations in the KRAS, BRAF, PIK3CA, JAK1 and JAK2 genes were evaluated in 94 HNSCCs by direct DNA sequencing analysis using cDNA synthesized from RNA extracted from patient tumor cells. All patients evaluated had wild-type KRAS, BRAF and PIK3CA genes. Furthermore, although some known polymorphisms have been found in JAK1 genes (rs45598436, rs17127063, rs2230587, rs3737139, rs2230588 and rs12129819) and JAK2 (rs10429491, rs2230723, rs2230724 and rs41316003), no mutation could be detected. Our data indicate that mutations in these kinase genes seem to be rare events in HNSCC.