title: Human enhancer of filamentation 1, a novel p130cas-like docking protein, associates with focal adhesion kinase and induces pseudohyphal growth in Saccharomyces cerevisiae.
abstract: Budding in Saccharomyces cerevisiae follows a genetically programmed pattern of cell division which can be regulated by external signals. On the basis of the known functional conservation between a number of mammalian oncogenes and antioncogenes with genes in the yeast budding pathway, we used enhancement of pseudohyphal budding in S. cerevisiae by human proteins expressed from a HeLa cDNA library as a morphological screen to identify candidate genes that coordinate cellular signaling and morphology. In this report, we describe the isolation and characterization of human enhancer of filamentation 1 (HEF1), an SH3-domain-containing protein that is similar in structure to pl30cas, a recently identified docking protein that is a substrate for phosphorylation by a number of oncogenic tyrosine kinases. In contrast to p130cas, the expression of HEF1 appears to be tissue specific. Further, whereas p130cas is localized predominantly at focal adhesions, immunofluorescence indicates that HEF1 localizes to both the cell periphery and the cell nucleus and is differently localized in fibroblasts and epithelial cells, suggesting a more complex role in cell signalling. Through immunoprecipitation and two-hybrid analysis, we demonstrate a direct physical interaction between HEF1 and p130cas, as well as an interaction of the SH3 domain of HEF1 with two discrete proline-rich regions of focal adhesion kinase. Finally, we demonstrate that as with p130cas, transformation with the oncogene v-abl results in an increase in tyrosine phosphorylation on HEF1, mediated by a direct association between HEF1 and v-Abl. We anticipate that HEF1 may prove to be an important linking element between extracellular signalling and regulation of the cytoskeleton.
authors.affiliation: Division of Basic Science, Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA.
authors.forename: S F
authors.initials: SF
authors.lastname: Law
authors.forename: J
authors.initials: J
authors.lastname: Estojak
authors.forename: B
authors.initials: B
authors.lastname: Wang
authors.forename: T
authors.initials: T
authors.lastname: Mysliwiec
authors.forename: G
authors.initials: G
authors.lastname: Kruh
authors.forename: E A
authors.initials: EA
authors.lastname: Golemis
mesh_terms: D048868:Adaptor Proteins, Signal Transducing; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D002455:Cell Division; D003001:Cloning, Molecular; D050719:Crk-Associated Substrate Protein; D017931:DNA Primers; D018076:DNA, Complementary; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; D015723:Gene Library; D006367:HeLa Cells; D006801:Humans; D008322:Mammals; D008715:Methionine; D008969:Molecular Sequence Data; D009857:Oncogenes; D010750:Phosphoproteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011506:Proteins; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D050717:Retinoblastoma-Like Protein p130; D012441:Saccharomyces cerevisiae / Q000254:growth & development*; D017386:Sequence Homology, Amino Acid; D014443:Tyrosine
chemical_list: D048868:Adaptor Proteins, Signal Transducing; C493841:BCAR1 protein, human; C493843:Bcar1 protein, rat; D015815:Cell Adhesion Molecules; D050719:Crk-Associated Substrate Protein; D017931:DNA Primers; D018076:DNA, Complementary; C099942:NEDD9 protein, human; D010750:Phosphoproteins; D011506:Proteins; D011993:Recombinant Fusion Proteins; D050717:Retinoblastoma-Like Protein p130; D014443:Tyrosine; D008715:Methionine; D011505:Protein-Tyrosine Kinases; D051417:Focal Adhesion Kinase 1; D051416:Focal Adhesion Protein-Tyrosine Kinases; C496050:PTK2 protein, human; C496052:Ptk2 protein, rat