scholarly journals The v-Src SH3 domain binds phosphatidylinositol 3'-kinase.

1993 ◽  
Vol 13 (9) ◽  
pp. 5225-5232 ◽  
Author(s):  
X Liu ◽  
L E Marengere ◽  
C A Koch ◽  
T Pawson
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Chicken Embryo ◽  
Sh3 Domain ◽  
Sh2 Domain ◽  
Src Tyrosine Kinase ◽  
Amino Terminal ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Fibroblasts transformed by v-src or by related oncogenes encoding activated tyrosine kinases contain elevated levels of polyphosphoinositides with phosphate at the D-3 position of the inositol ring, as a result of the activation of phosphatidylinositol (PI) 3'-kinase. v-src-transformed cells also contain increased levels of PI 3'-kinase activity immunoprecipitable with anti-phosphotyrosine antibodies; furthermore, PI 3'-kinase can be detected in association with the v-Src tyrosine kinase. To identify regions of v-Src that can interact with PI 3'-kinase, the v-Src SH2 and SH3 domains were expressed in bacteria and incubated with lysates of normal chicken embryo fibroblasts. In vitro, the v-Src SH3 domain, but not the SH2 domain, bound PI 3'-kinase in lysates of uninfected chicken embryo fibroblasts. Substitutions of two highly conserved SH3 residues implicated in ligand binding abolished the ability of the v-Src SH3 domain to associate with PI 3'-kinase. Furthermore, the v-Src SH3 domain bound in vitro to the amino-terminal region of the p85 alpha subunit of PI 3'-kinase. These results suggest that the v-Src SH3 domain may mediate an interaction between the v-Src tyrosine kinase and PI 3'-kinase, by direct binding to p85.

The v-Src SH3 domain binds phosphatidylinositol 3'-kinase

1993 ◽  
Vol 13 (9) ◽  
pp. 5225-5232
Author(s):  
X Liu ◽  
L E Marengere ◽  
C A Koch ◽  
T Pawson
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Chicken Embryo ◽  
Sh3 Domain ◽  
Sh2 Domain ◽  
Src Tyrosine Kinase ◽  
Amino Terminal ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Fibroblasts transformed by v-src or by related oncogenes encoding activated tyrosine kinases contain elevated levels of polyphosphoinositides with phosphate at the D-3 position of the inositol ring, as a result of the activation of phosphatidylinositol (PI) 3'-kinase. v-src-transformed cells also contain increased levels of PI 3'-kinase activity immunoprecipitable with anti-phosphotyrosine antibodies; furthermore, PI 3'-kinase can be detected in association with the v-Src tyrosine kinase. To identify regions of v-Src that can interact with PI 3'-kinase, the v-Src SH2 and SH3 domains were expressed in bacteria and incubated with lysates of normal chicken embryo fibroblasts. In vitro, the v-Src SH3 domain, but not the SH2 domain, bound PI 3'-kinase in lysates of uninfected chicken embryo fibroblasts. Substitutions of two highly conserved SH3 residues implicated in ligand binding abolished the ability of the v-Src SH3 domain to associate with PI 3'-kinase. Furthermore, the v-Src SH3 domain bound in vitro to the amino-terminal region of the p85 alpha subunit of PI 3'-kinase. These results suggest that the v-Src SH3 domain may mediate an interaction between the v-Src tyrosine kinase and PI 3'-kinase, by direct binding to p85.

In vivo effect of sodium orthovanadate on pp60c-src kinase

1987 ◽  
Vol 7 (3) ◽  
pp. 1139-1147
Author(s):  
J W Ryder ◽  
J A Gordon
Keyword(s):  
Tyrosine Kinase ◽  
Chicken Embryo ◽  
Sodium Orthovanadate ◽  
Normal Cells ◽  
Amino Terminal ◽  
Carboxyl Terminal ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

We have compared the tyrosine kinase activity of pp60c-src isolated from intact chicken embryo fibroblasts treated with micromolar sodium orthovanadate for 4 h and from untreated cells. We found an approximate 50% reduction in both autophosphorylation of pp60c-src and phosphorylation of casein when examined in the immune complex kinase assay. The reduction of in vitro enzymatic activity correlated with a vanadate-induced increase in in vivo phosphorylation of pp60c-src at the major site of tyrosine phosphorylation in the carboxyl-terminal half of the molecule and at serine in the amino-terminal half of the molecule. Our observations in vivo and those of Courtneidge in vitro (EMBO J. 4:1471-1477, 1985) suggest that vanadate may enhance a cellular regulatory mechanism that inhibits the activity of pp60c-src in normal cells. A likely candidate for this mechanism is phosphorylation at a tyrosine residue distinct from tyrosine 416, probably tyrosine 527 in the carboxyl-terminal sequence of amino acids unique to pp60c-src. The regulatory role, if any, of serine phosphorylation in pp60c-src remains unclear. The 36-kilodalton phosphoprotein, a substrate of pp60v-src, showed a significant phosphorylation at tyrosine after treatment of normal chicken embryo fibroblasts with vanadate. Assuming that pp60c-src is inhibited intracellularly by vanadate, either another tyrosine kinase is stimulated by vanadate (e.g., a growth factor receptor) or the 36-kilodalton phosphoprotein in normal cells is no longer rapidly dephosphorylated by a tyrosine phosphatase in the presence of vanadate.

scholarly journals In vivo effect of sodium orthovanadate on pp60c-src kinase.

1987 ◽  
Vol 7 (3) ◽  
pp. 1139-1147 ◽  
Author(s):  
J W Ryder ◽  
J A Gordon
Keyword(s):  
Tyrosine Kinase ◽  
Chicken Embryo ◽  
Sodium Orthovanadate ◽  
Normal Cells ◽  
Amino Terminal ◽  
Carboxyl Terminal ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

We have compared the tyrosine kinase activity of pp60c-src isolated from intact chicken embryo fibroblasts treated with micromolar sodium orthovanadate for 4 h and from untreated cells. We found an approximate 50% reduction in both autophosphorylation of pp60c-src and phosphorylation of casein when examined in the immune complex kinase assay. The reduction of in vitro enzymatic activity correlated with a vanadate-induced increase in in vivo phosphorylation of pp60c-src at the major site of tyrosine phosphorylation in the carboxyl-terminal half of the molecule and at serine in the amino-terminal half of the molecule. Our observations in vivo and those of Courtneidge in vitro (EMBO J. 4:1471-1477, 1985) suggest that vanadate may enhance a cellular regulatory mechanism that inhibits the activity of pp60c-src in normal cells. A likely candidate for this mechanism is phosphorylation at a tyrosine residue distinct from tyrosine 416, probably tyrosine 527 in the carboxyl-terminal sequence of amino acids unique to pp60c-src. The regulatory role, if any, of serine phosphorylation in pp60c-src remains unclear. The 36-kilodalton phosphoprotein, a substrate of pp60v-src, showed a significant phosphorylation at tyrosine after treatment of normal chicken embryo fibroblasts with vanadate. Assuming that pp60c-src is inhibited intracellularly by vanadate, either another tyrosine kinase is stimulated by vanadate (e.g., a growth factor receptor) or the 36-kilodalton phosphoprotein in normal cells is no longer rapidly dephosphorylated by a tyrosine phosphatase in the presence of vanadate.

scholarly journals Mutagenic analysis of the roles of SH2 and SH3 domains in regulation of the Abl tyrosine kinase.

1994 ◽  
Vol 14 (5) ◽  
pp. 2883-2894 ◽  
Author(s):  
B J Mayer ◽  
D Baltimore
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Sh3 Domain ◽  
Sh2 Domain ◽  
Sh3 Domains ◽  
Sh2 Domains ◽  
Abl Tyrosine Kinase ◽  
Transforming Activity

We have used in vitro mutagenesis to examine in detail the roles of two modular protein domains, SH2 and SH3, in the regulation of the Abl tyrosine kinase. As previously shown, the SH3 domain suppresses an intrinsic transforming activity of the normally nontransforming c-Abl product in vivo. We show here that this inhibitory activity is extremely position sensitive, because mutants in which the position of the SH3 domain within the protein is subtly altered are fully transforming. In contrast to the case in vivo, the SH3 domain has no effect on the in vitro kinase activity of the purified protein. These results are consistent with a model in which the SH3 domain binds a cellular inhibitory factor, which in turn must physically interact with other parts of the kinase. Unlike the SH3 domain, the SH2 domain is required for transforming activity of activated Abl alleles. We demonstrate that SH2 domains from other proteins (Ras-GTPase-activating protein, Src, p85 phosphatidylinositol 3-kinase subunit, and Crk) can complement the absence of the Abl SH2 domain and that mutants with heterologous SH2 domains induce altered patterns of tyrosine-phosphorylated proteins in vivo. The positive function of the SH2 domain is relatively position independent, and the effect of multiple SH2 domains appears to be additive. These results suggest a novel mechanism for regulation of tyrosine kinases in which the SH2 domain binds to, and thereby enhances the phosphorylation of, a subset of proteins phosphorylated by the catalytic domain. Our data also suggest that the roles of the SH2 and SH3 domains in the regulation of Abl are different in several respects from the roles proposed for these domains in the closely related Src family of tyrosine kinases.

scholarly journals Mutagenic analysis of the roles of SH2 and SH3 domains in regulation of the Abl tyrosine kinase

1994 ◽  
Vol 14 (5) ◽  
pp. 2883-2894
Author(s):  
B J Mayer ◽  
D Baltimore
Keyword(s):  
Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Sh3 Domain ◽  
Sh2 Domain ◽  
Sh3 Domains ◽  
Sh2 Domains ◽  
Abl Tyrosine Kinase ◽  
Transforming Activity

We have used in vitro mutagenesis to examine in detail the roles of two modular protein domains, SH2 and SH3, in the regulation of the Abl tyrosine kinase. As previously shown, the SH3 domain suppresses an intrinsic transforming activity of the normally nontransforming c-Abl product in vivo. We show here that this inhibitory activity is extremely position sensitive, because mutants in which the position of the SH3 domain within the protein is subtly altered are fully transforming. In contrast to the case in vivo, the SH3 domain has no effect on the in vitro kinase activity of the purified protein. These results are consistent with a model in which the SH3 domain binds a cellular inhibitory factor, which in turn must physically interact with other parts of the kinase. Unlike the SH3 domain, the SH2 domain is required for transforming activity of activated Abl alleles. We demonstrate that SH2 domains from other proteins (Ras-GTPase-activating protein, Src, p85 phosphatidylinositol 3-kinase subunit, and Crk) can complement the absence of the Abl SH2 domain and that mutants with heterologous SH2 domains induce altered patterns of tyrosine-phosphorylated proteins in vivo. The positive function of the SH2 domain is relatively position independent, and the effect of multiple SH2 domains appears to be additive. These results suggest a novel mechanism for regulation of tyrosine kinases in which the SH2 domain binds to, and thereby enhances the phosphorylation of, a subset of proteins phosphorylated by the catalytic domain. Our data also suggest that the roles of the SH2 and SH3 domains in the regulation of Abl are different in several respects from the roles proposed for these domains in the closely related Src family of tyrosine kinases.

Cellular proteins homologous to the viral yes gene product

1986 ◽  
Vol 6 (8) ◽  
pp. 2839-2846
Author(s):  
M Sudol ◽  
H Hanafusa
Keyword(s):  
Chicken Embryo ◽  
Peptide Mapping ◽  
Kinase Assay ◽  
Lac Operon ◽  
Amino Terminal ◽  
Embryo Fibroblasts ◽  
Purified Antigen ◽  
Chicken Embryo Fibroblasts

We raised antibodies in rabbits against the amino-terminal portion of the viral yes protein produced in bacteria with the use of an expression vector based on the lac operon. The anti-yes serum thus obtained precipitated P90gag-yes from Yamaguchi 73 virus-transformed chicken embryo fibroblasts, and this immunoprecipitation was blocked by the purified antigen. The anti-yes serum did not recognize viral src, fps, or fgr proteins. Affinity-purified anti-yes immunoglobulin G (IgG) precipitated two proteins of 59 and 62 kilodaltons from lysates of normal chicken embryo fibroblasts. Two-dimensional tryptic peptide mapping showed that these proteins are closely related to P90gag-yes and that they are different from pp60c-src. Similar to P90gag-yes, the 59- and 62-kilodalton proteins were phosphorylated exclusively on tyrosine in an in vitro kinase reaction, whereas in vivo they were phosphorylated on serine and, to a lesser extent, on tyrosine as well. Expression of the 59- and 62-kilodalton proteins, determined by the immune complex kinase assay, was relatively high in brain, retina, kidney, and liver. The presence in normal chicken embryo fibroblasts and in chicken kidney of two transcripts, 3.7 and 3.9 kilobases in length, that hybridize with a yes-specific DNA probe, as well as the two proteins recognized by anti-yes IgG, suggests either differential splicing of cellular yes gene transcripts or the existence of another yes-related gene.

scholarly journals Cellular proteins homologous to the viral yes gene product.

1986 ◽  
Vol 6 (8) ◽  
pp. 2839-2846 ◽  
Author(s):  
M Sudol ◽  
H Hanafusa
Keyword(s):  
Chicken Embryo ◽  
Peptide Mapping ◽  
Kinase Assay ◽  
Lac Operon ◽  
Amino Terminal ◽  
Embryo Fibroblasts ◽  
Purified Antigen ◽  
Chicken Embryo Fibroblasts

We raised antibodies in rabbits against the amino-terminal portion of the viral yes protein produced in bacteria with the use of an expression vector based on the lac operon. The anti-yes serum thus obtained precipitated P90gag-yes from Yamaguchi 73 virus-transformed chicken embryo fibroblasts, and this immunoprecipitation was blocked by the purified antigen. The anti-yes serum did not recognize viral src, fps, or fgr proteins. Affinity-purified anti-yes immunoglobulin G (IgG) precipitated two proteins of 59 and 62 kilodaltons from lysates of normal chicken embryo fibroblasts. Two-dimensional tryptic peptide mapping showed that these proteins are closely related to P90gag-yes and that they are different from pp60c-src. Similar to P90gag-yes, the 59- and 62-kilodalton proteins were phosphorylated exclusively on tyrosine in an in vitro kinase reaction, whereas in vivo they were phosphorylated on serine and, to a lesser extent, on tyrosine as well. Expression of the 59- and 62-kilodalton proteins, determined by the immune complex kinase assay, was relatively high in brain, retina, kidney, and liver. The presence in normal chicken embryo fibroblasts and in chicken kidney of two transcripts, 3.7 and 3.9 kilobases in length, that hybridize with a yes-specific DNA probe, as well as the two proteins recognized by anti-yes IgG, suggests either differential splicing of cellular yes gene transcripts or the existence of another yes-related gene.

Ubiquitin is a heat shock protein in chicken embryo fibroblasts

1985 ◽  
Vol 5 (5) ◽  
pp. 949-956
Author(s):  
U Bond ◽  
M J Schlesinger
Keyword(s):  
Heat Shock ◽  
Chicken Embryo ◽  
Recombinant Dna ◽  
Protein Product ◽  
Amino Acid Sequences ◽  
In Vitro Translation ◽  
Bovine Ubiquitin ◽  
Embryo Fibroblasts ◽  
Chicken Embryo Fibroblasts

Clones containing heat-inducible mRNA sequences were selected from a cDNA library prepared from polyadenylated RNA isolated from heat-shocked chicken embryo fibroblasts. One recombinant DNA clone, designated clone 7, hybridized to a 1.2-kilobase RNA that was present in normal cells and increased fivefold during heat shock. Clone 7 also hybridized to an RNA species of 1.7 kilobases that was present exclusively in heat-shocked cells. In vitro translation of mRNA hybrid selected from clone 7 produced a protein product with a molecular weight of approximately 8,000. Increased synthesis of a protein of similar size was detected in chicken embryo fibroblasts after heat shock. DNA sequence analysis of clone 7 indicated its protein product has amino acid sequences identical to bovine ubiquitin. In addition, clone 7 contains tandem copies of the ubiquitin sequences contiguous to each other with no untranslated sequences between them. We discuss some possible roles for ubiquitin in the heat shock response.

Transformation of chicken embryo fibroblasts and tumor induction by the middle T antigen of polyomavirus carried in an avian retroviral vector

1986 ◽  
Vol 6 (5) ◽  
pp. 1545-1551
Author(s):  
S Kornbluth ◽  
F R Cross ◽  
M Harbison ◽  
H Hanafusa
Keyword(s):  
Chicken Embryo ◽  
Mammalian Cells ◽  
Cell Transformation ◽  
T Antigen ◽  
Rous Sarcoma ◽  
Embryo Fibroblasts ◽  
Polyomavirus Middle T Antigen ◽  
Middle T Antigen ◽  
Chicken Embryo Fibroblasts

The middle T antigen of polyomavirus transformed primary chicken embryo fibroblasts when expressed from a replication-competent avian retrovirus. This in vitro-constructed retrovirus, SRMT1, is a variant of Rous sarcoma virus that encodes the middle T antigen in place of v-src. Inoculation of SRMT1 into 1-week-old chickens rapidly induced hemangiomas and hemangiosarcomas. As shown with mammalian cells infected with polyomavirus, polyomavirus middle T antigen appears to be associated with p60c-src in chicken cells infected with SRMT1. When lysates of SRMT1-infected cells immunoprecipitated with either a monoclonal antibody against p60src or anti-T serum were assayed in an in vitro kinase reaction, the middle T antigen was heavily phosphorylated. To see whether an excess of p60c-src could alter the extent of phosphorylation of the middle T protein or the process of cell transformation by middle T, cells were doubly infected with SRMT1 and NY501, a virus which overexpresses p60c-src. Doubly infected chicken embryo fibroblasts transformed with the same kinetics and were morphologically indistinguishable from chicken embryo fibroblasts infected with SRMT1 alone. Phosphorylation of the middle T antigen was elevated two- to fivefold relative to cells infected only with SRMT1.

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