scholarly journals Contributions of F-BAR and SH2 Domains of Fes Protein Tyrosine Kinase for Coupling to the FcεRI Pathway in Mast Cells

2008 ◽  
Vol 29 (2) ◽  
pp. 389-401 ◽  
Author(s):  
Victor A. McPherson ◽  
Stephanie Everingham ◽  
Robert Karisch ◽  
Julie A. Smith ◽  
Christian M. Udell ◽  
...  
Keyword(s):  
Mast Cells ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Regulatory Protein ◽  
Sh2 Domain ◽  
Wild Type ◽  
Protein Tyrosine ◽  
Bar Domain ◽  
Sh2 Domains

ABSTRACT This study investigates the roles of Fer-CIP4 homology (FCH)-Bin/amphiphysin/Rvs (F-BAR) and SH2 domains of Fes protein tyrosine kinase in regulating its activation and signaling downstream of the high-affinity immunoglobulin G (IgE) receptor (FcεRI) in mast cells. Homology modeling of the Fes F-BAR domain revealed conservation of some basic residues implicated in phosphoinositide binding (R113/K114). The Fes F-BAR can bind phosphoinositides and induce tubulation of liposomes in vitro. Mutation of R113/K114 to uncharged residues (RK/QQ) caused a significant reduction in phosphoinositide binding in vitro and a more diffuse cytoplasmic localization in transfected COS-7 cells. RBL-2H3 mast cells expressing full-length Fes carrying the RK/QQ mutation show defects in FcεRI-induced Fes tyrosine phosphorylation and degranulation compared to cells expressing wild-type Fes. This correlated with reduced localization to Lyn kinase-containing membrane fractions for the RK/QQ mutant compared to wild-type Fes in mast cells. The Fes SH2 domain also contributes to Fes signaling in mast cells, via interactions with the phosphorylated FcεRI β chain and the actin regulatory protein HS1. We show that Fes phosphorylates C-terminal tyrosine residues in HS1 implicated in actin stabilization. Thus, coordinated actions of the F-BAR and SH2 domains of Fes allow for coupling to FcεRI signaling and potential regulation the actin reorganization in mast cells.

scholarly journals Regulation and Function of Syk Tyrosine Kinase in Mast Cell Signaling and Beyond

2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Rodrigo Orlandini de Castro
Keyword(s):  
Mast Cell ◽  
Mast Cells ◽  
Tyrosine Kinase ◽  
Tyrosine Phosphorylation ◽  
Conformational Changes ◽  
Protein Tyrosine Kinase ◽  
Critical Role ◽  
Wild Type ◽  
And Function

The protein tyrosine kinase Syk plays a critical role in FcεRI signaling in mast cells. Binding of Syk to phosphorylated immunoreceptor tyrosine-based activation motifs (p-ITAM) of the receptor subunits results in conformational changes and tyrosine phosphorylation at multiple sites that leads to activation of Syk. The phosphorylated tyrosines throughout the molecule play an important role in the regulation of Syk-mediated signaling. Reconstitution of receptor-mediated signaling in Syk-/- cells by wild-type Syk or mutants which have substitution of these tyrosines with phenylalanine together with in vitro assays has been useful strategies to understand the regulation and function of Syk.

scholarly journals Multiple SH2-mediated interactions in v-src-transformed cells.

1992 ◽  
Vol 12 (3) ◽  
pp. 1366-1374 ◽  
Author(s):  
C A Koch ◽  
M F Moran ◽  
D Anderson ◽  
X Q Liu ◽  
G Mbamalu ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Kinase Domain ◽  
Sh2 Domain ◽  
Protein Tyrosine ◽  
Sh2 Domains ◽  
Phosphorylated Proteins

The Src homology 2 (SH2) domain is a noncatalytic region which is conserved among a number of signaling and transforming proteins, including cytoplasmic protein-tyrosine kinases and Ras GTPase-activating protein (GAP). Genetic and biochemical data indicate that the SH2 domain of the p60v-src (v-Src) protein-tyrosine kinase is required for full v-src transforming activity and may direct the association of v-Src with specific tyrosine-phosphorylated proteins. To test the ability of the v-Src SH2 domain to mediate protein-protein interactions, v-Src polypeptides were expressed as fusion proteins in Escherichia coli. The bacterial v-Src SH2 domain bound a series of tyrosine-phosphorylated proteins in a lysate of v-src-transformed Rat-2 cells, including prominent species of 130 and 62 kDa (p130 and p62). The p130 and p62 tyrosine-phosphorylated proteins that complexed v-Src SH2 in vitro also associated with v-Src in v-src-transformed Rat-2 cells; this in vivo binding was dependent on the v-Src SH2 domain. In addition to binding soluble p62 and p130, the SH2 domains of v-Src, GAP, and v-Crk directly recognized these phosphotyrosine-containing proteins which had been previously denatured and immobilized on a filter. In addition, the SH2 domains of GAP and v-Crk bound to the GAP-associated protein p190 immobilized on a nitrocellulose membrane. These results show that SH2 domains bind directly to tyrosine-phosphorylated proteins and that the Src SH2 domain can bind phosphorylated targets of the v-Src kinase domain.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The nonreceptor protein-tyrosine kinase CSK complexes directly with the GTPase-activating protein-associated p62 protein in cells expressing v-Src or activated c-Src.

1995 ◽  
Vol 15 (9) ◽  
pp. 4908-4920 ◽  
Author(s):  
K Neet ◽  
T Hunter
Keyword(s):  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Sh2 Domain ◽  
Gtpase Activating Protein ◽  
3T3 Cells ◽  
Protein Tyrosine ◽  
Src Activation ◽  
Nih 3T3 ◽  
Nih 3T3 Cells

CSK is a predominantly cytosolic protein-tyrosine kinase (PTK) that negatively regulates Src family PTKs by phosphorylation of a conserved tyrosine near their C termini. Little is known about how CSK itself is regulated. On the basis of immunofluorescence studies, a model has been proposed that when c-Src is activated, it is redistributed to podosomes, in which substrates become phosphorylated, creating binding sites for CSK. CSK is recruited to these sites of c-Src activation via its SH2 and SH3 domains and is then in a position to downregulate c-Src activity (B. W. Howell and J. A. Cooper, Mol. Cell. Biol. 14:5402-5411, 1994). To identify phosphotyrosine (P.Tyr)-containing proteins that may mediate translocation of CSK due to c-Src activation, we have examined the whole spectrum of P.Tyr-containing proteins that associate with CSK in v-Src NIH 3T3 cells by anti-P.Tyr immunoblotting. Nine P.Tyr-containing proteins coimmunoprecipitated with CSK from v-Src NIH 3T3 cells. One of these, an approximately 62-kDa protein, also associated with CSK in NIH 3T3 cells treated with vanadate prior to lysis and in NIH 3T3 cells expressing an activated c-Src mutant. This 62-kDa protein was shown to be identical to the GTPase-activating protein (GAP)-associated p62 (GAP-A.p62) protein. The interaction between CSK and GAP-A.p62 could be reconstituted in vitro with glutathione S-transferase fusion proteins containing full-length CSK or the CSK SH2 domain. Furthermore, our data show that CSK interacts directly with GAP.A-p62 and that the complex between the two proteins is localized in subcellular membrane or cytoskeletal fractions. Our results suggest that GAP-A.p62 may function as a docking protein and may mediate translocation of proteins, including GAP and CSK, to membrane or cytoskeletal regions upon c-Src activation.

Multiple SH2-mediated interactions in v-src-transformed cells

1992 ◽  
Vol 12 (3) ◽  
pp. 1366-1374
Author(s):  
C A Koch ◽  
M F Moran ◽  
D Anderson ◽  
X Q Liu ◽  
G Mbamalu ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Kinase Domain ◽  
Sh2 Domain ◽  
Protein Tyrosine ◽  
Sh2 Domains ◽  
Phosphorylated Proteins

The Src homology 2 (SH2) domain is a noncatalytic region which is conserved among a number of signaling and transforming proteins, including cytoplasmic protein-tyrosine kinases and Ras GTPase-activating protein (GAP). Genetic and biochemical data indicate that the SH2 domain of the p60v-src (v-Src) protein-tyrosine kinase is required for full v-src transforming activity and may direct the association of v-Src with specific tyrosine-phosphorylated proteins. To test the ability of the v-Src SH2 domain to mediate protein-protein interactions, v-Src polypeptides were expressed as fusion proteins in Escherichia coli. The bacterial v-Src SH2 domain bound a series of tyrosine-phosphorylated proteins in a lysate of v-src-transformed Rat-2 cells, including prominent species of 130 and 62 kDa (p130 and p62). The p130 and p62 tyrosine-phosphorylated proteins that complexed v-Src SH2 in vitro also associated with v-Src in v-src-transformed Rat-2 cells; this in vivo binding was dependent on the v-Src SH2 domain. In addition to binding soluble p62 and p130, the SH2 domains of v-Src, GAP, and v-Crk directly recognized these phosphotyrosine-containing proteins which had been previously denatured and immobilized on a filter. In addition, the SH2 domains of GAP and v-Crk bound to the GAP-associated protein p190 immobilized on a nitrocellulose membrane. These results show that SH2 domains bind directly to tyrosine-phosphorylated proteins and that the Src SH2 domain can bind phosphorylated targets of the v-Src kinase domain.(ABSTRACT TRUNCATED AT 250 WORDS)

Stable association of pp60src and pp59fyn with the focal adhesion-associated protein tyrosine kinase, pp125FAK

1994 ◽  
Vol 14 (1) ◽  
pp. 147-155
Author(s):  
B S Cobb ◽  
M D Schaller ◽  
T H Leu ◽  
J T Parsons
Keyword(s):  
Focal Adhesion ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Src Family Kinases ◽  
Protein Tyrosine Kinases ◽  
Protein Tyrosine ◽  
Sh2 Domains ◽  
Embryo Cells ◽  
Stable Association

Changes in cellular growth and dramatic alterations in cell morphology and adhesion are common features of cells transformed by oncogenic protein tyrosine kinases, such as pp60src and other members of the Src family. In this report, we present evidence for the stable association of two Src family kinases (pp60src and pp59fyn) with tyrosine-phosphorylated forms of a focal adhesion-associated protein tyrosine kinase, pp125FAK. In Src-transformed chicken embryo cells, most of the pp125FAK was stably complexed with activated pp60src (e.g., pp60(527F). The stable association of pp125FAK with pp60(527F) in vivo required the structural integrity of the Src SH2 domain. The association of pp60(527F) and pp125FAK could be reconstituted in vitro by incubation of normal cell extracts with glutathione S-transferase fusion proteins containing SH2 or SH3/SH2 domains of pp60src. Furthermore, the association of isolated SH2 or SH3/SH2 domains with in vitro 32P-labeled pp125FAK protected the major site of pp125FAK autophosphorylation from digestion with a tyrosine phosphatase, indicating that the autophosphorylation site of pp125FAK participates in binding with Src. Immunoprecipitation of Src family kinases from extracts of normal chicken embryo cells revealed stable complexes of pp59fyn and tyrosine-phosphorylated pp125FAK. These data provide evidence for a direct interaction between two cytoplasmic nonreceptor protein tyrosine kinases and suggest that Src may contribute to changes in pp125FAK regulation in transformed cells. Furthermore, pp125FAK may directly participate in the targeting of pp59fyn or possibly other Src family kinases to focal adhesions in normal cells.

Phosphatidylinositol (PI) 3-kinase and PI 4-kinase binding to the CD4-p56lck complex: the p56lck SH3 domain binds to PI 3-kinase but not PI 4-kinase

1993 ◽  
Vol 13 (12) ◽  
pp. 7708-7717
Author(s):  
K V Prasad ◽  
R Kapeller ◽  
O Janssen ◽  
H Repke ◽  
J S Duke-Cohan ◽  
...  
Keyword(s):  
T Cells ◽  
Tyrosine Kinase ◽  
Protein Tyrosine Kinase ◽  
Sh3 Domain ◽  
Sh2 Domain ◽  
Activation Process ◽  
Lipid Kinase ◽  
Sh3 Domains ◽  
Protein Tyrosine ◽  
Hiv 1

CD4 serves as a receptor for major histocompatibility complex class II antigens and as a receptor for the human immunodeficiency virus type 1 (HIV-1) viral coat protein gp120. It is coupled to the protein-tyrosine kinase p56lck, an interaction necessary for an optimal response of certain T cells to antigen. In addition to the protein-tyrosine kinase domain, p56lck possesses Src homology 2 and 3 (SH2 and SH3) domains as well as a unique N-terminal region. The mechanism by which p56lck generates intracellular signals is unclear, although it has the potential to interact with various downstream molecules. One such downstream target is the lipid kinase phosphatidylinositol 3-kinase (PI 3-kinase), which has been found to bind to activated pp60src and receptor-tyrosine kinases. In this study, we verified that PI 3-kinase associates with the CD4:p56lck complex as judged by the presence of PI 3-phosphate generated from anti-CD4 immunoprecipitates and detected by high-pressure liquid chromatographic analysis. However, surprisingly, CD4-p56lck was also found to associate with another lipid kinase, phosphatidylinositol 4-kinase (PI 4-kinase). The level of associated PI 4-kinase was generally higher than PI 3-kinase activity. HIV-1 gp120 and antibody-mediated cross-linking induced a 5- to 10-fold increase in the level of CD4-associated PI 4- and PI 3-kinases. The use of glutathione S-transferase fusion proteins carrying Lck-SH2, Lck-SH3, and Lck-SH2/SH3 domains showed PI 3-kinase binding to the SH3 domain of p56lck, an interaction facilitated by the presence of an adjacent SH2 domain. PI 4-kinase bound to neither the SH2 nor the SH3 domain of p56lck. CD4-p56lck contributes PI 3- and PI 4-kinase to the activation process of T cells and may play a role in HIV-1-induced immune defects.

Characterization of elk, a brain-specific receptor tyrosine kinase

1991 ◽  
Vol 11 (5) ◽  
pp. 2496-2502
Author(s):  
V Lhoták ◽  
P Greer ◽  
K Letwin ◽  
T Pawson
Keyword(s):  
Tyrosine Kinase ◽  
Receptor Tyrosine Kinase ◽  
Tyrosine Kinases ◽  
Protein Tyrosine Kinase ◽  
Catalytic Domain ◽  
Signal Sequence ◽  
Tyrosine Kinase Domain ◽  
Rat Tissues ◽  
Protein Tyrosine

The elk gene encodes a novel receptorlike protein-tyrosine kinase, which belongs to the eph subfamily. We have previously identified a partial cDNA encompassing the elk catalytic domain (K. Letwin, S.-P. Yee, and T. Pawson, Oncogene 3:621-678, 1988). Using this cDNA as a probe, we have isolated cDNAs spanning the entire rat elk coding sequence. The predicted Elk protein contains all the hallmarks of a receptor tyrosine kinase, including an N-terminal signal sequence, a cysteine-rich extracellular domain, a membrane-spanning segment, a cytoplasmic tyrosine kinase domain, and a C-terminal tail. In both amino acid sequence and overall structure, Elk is most similar to the Eph and Eck protein-tyrosine kinases, suggesting that the eph, elk, and eck genes encode members of a new subfamily of receptorlike tyrosine kinases. Among rat tissues, elk expression appears restricted to brain and testes, with the brain having higher levels of both elk RNA and protein. Elk protein immunoprecipitated from a rat brain lysate becomes phosphorylated on tyrosine in an in vitro kinase reaction, consistent with the prediction that the mammalian elk gene encodes a tyrosine kinase capable of autophosphorylation. The characteristics of the Elk tyrosine kinase suggest that it may be involved in cell-cell interactions in the nervous system.

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