Cbl-associated protein is tyrosine phosphorylated by c-Abl and c-Src kinases

Background  

The c-Cbl-associated protein (CAP), also known as ponsin, localizes to focal adhesions and stress fibers and is involved in signaling events. Phosphorylation has been described for the other two members of the sorbin homology family, vinexin and ArgBP2, but no data exist about the putative phosphorylation of CAP. According to previous findings, CAP binds to tyrosine kinase c-Abl. However, it is not known if CAP is a substrate of c-Abl or other tyrosine kinases or if phosphorylation regulates its localization.     

Coexpression of Stem Cell Factor andc-kitin Embryonic and Adult Liver

Stem cell factor and its receptorc-kitconstitute an important signal transduction system implicated in survival, proliferation, and differentiation of stem cells in hematopoiesis, gametogenesis, and melanogenesis. In the present study we used both immunocytochemical methods and Western analysis to demonstrate the presence of this cytokine/receptor system in both embryonic and adult rat liver. Stem cell factor was present in the ductular cells around the portal vein during the late embryonic stage of the liver. In the adult liver both bile ducts and bile ductules were positive for stem cell factor andc-kit.When the activation of the liver stem cell compartment was induced by combining administration of acetylaminofluorene and partial hepatectomy, both stem cell factor andc-kitwere expressed in the infiltrating oval cell population, but absent in the newly formed basophilic hepatocytes. Activation of oval cell proliferation following administration ofD-galactosamine also produced a similar but less prominent increase in the level of the stem cell factor. Our data suggest that the stem cell factor/c-kitsignal transduction system is involved in the development of bile ducts and that it may also be an important member of the growth factor/receptor systems associated with the biology of liver stem cells.     

Lipopolysaccharides of three classes of supersensitive mutants of Salmonella typhimurium

Abstract Cresyl violet acetate was found to be an appropriate redox-indicator dye in anaerobic culture media with low redox potentials. Low redox potentials ( E '_h−250 to −300 mV) in media were obtained by addition of dithiothreitol (DTT). DTT and cresyl violet acetate in media did not influence the total number of anaerobes cultured from human feces.