Modulation of Rabbit Reticulocyte Guanine Nucleotide Exchange Factor Activity by Casein Kinases 1 and 2 and Glycogen Synthase Kinase 3†

Biochemistry ◽  
1996 ◽  
Vol 35 (10) ◽  
pp. 3206-3212 ◽  
Author(s):  
Lalit P. Singh ◽  
Nancy D. Denslow ◽  
Albert J. Wahba
Keyword(s):  
Glycogen Synthase ◽  
Guanine Nucleotide Exchange Factor ◽  
Glycogen Synthase Kinase ◽  
Glycogen Synthase Kinase 3 ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Factor Activity ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Casein Kinases

scholarly journals TcR and TcR-CD28 Engagement of Protein Kinase B (PKB/AKT) and Glycogen Synthase Kinase-3 (GSK-3) Operates Independently of Guanine Nucleotide Exchange Factor VAV-1

2006 ◽  
Vol 281 (43) ◽  
pp. 32385-32394 ◽  
Author(s):  
Joanne E. Wood ◽  
Helga Schneider ◽  
Christopher E. Rudd
Keyword(s):  
T Cells ◽  
Protein Kinase ◽  
Glycogen Synthase ◽  
Protein Kinase B ◽  
Guanine Nucleotide Exchange Factor ◽  
Glycogen Synthase Kinase 3 ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

TcRζ/CD3 and TcRζ/CD3-CD28 signaling requires the guanine nucleotide exchange factor (GEF) Vav-1 as well as the activation of phosphatidylinositol 3-kinase, protein kinase B (PKB/AKT), and its inactivation of glycogen synthase kinase-3 (GSK-3). Whether these two pathways are connected or operate independently of each other in T-cells has been unclear. Here, we report that anti-CD3 and anti-CD3/CD28 can induce PKB and GSK-3α phosphorylation in the Vav-1–/– Jurkat cell line J. Vav.1 and in primary CD4-positive Vav-1–/– T-cells. Reduced GSK-3α phosphorylation was observed in Vav-1,2,3–/– T-cells together with a complete loss of FOXO1 phosphorylation. Furthermore, PKB and GSK-3 phosphorylation was unperturbed in the presence of GEF-inactive Vav-1 that inhibited interleukin-2 gene activation and a form of Src homology 2 domain-containing lymphocytic protein of 76-kDa (SLP-76) that is defective in binding to Vav-1. The pathway also was intact under conditions of c-Jun N-terminal kinase (JNK) inhibition and disruption of the actin cytoskeleton by cytochalasin D. Both events are down-stream targets of Vav-1. Overall, our findings indicate that the TcR and TcR-CD28 driven PKB-GSK-3 pathway can operate independently of Vav-1 in T-cells.

scholarly journals Decreased guanine nucleotide exchange factor activity in eIF2B-mutated patients

2004 ◽  
Vol 12 (7) ◽  
pp. 561-566 ◽  
Author(s):  
Anne Fogli ◽  
Raphael Schiffmann ◽  
Lynne Hugendubler ◽  
Patricia Combes ◽  
Enrico Bertini ◽  
...  
Keyword(s):  
Guanine Nucleotide Exchange Factor ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Factor Activity ◽  
Exchange Factor ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

scholarly journals A Burkholderia pseudomallei Type III Secreted Protein, BopE, Facilitates Bacterial Invasion of Epithelial Cells and Exhibits Guanine Nucleotide Exchange Factor Activity

2003 ◽  
Vol 185 (16) ◽  
pp. 4992-4996 ◽  
Author(s):  
Mark P. Stevens ◽  
Andrea Friebel ◽  
Lowrie A. Taylor ◽  
Michael W. Wood ◽  
Philip J. Brown ◽  
...  
Keyword(s):  
Burkholderia Pseudomallei ◽  
Guanine Nucleotide Exchange Factor ◽  
Secreted Protein ◽  
Guanine Nucleotide ◽  
Nucleotide Exchange ◽  
Factor Activity ◽  
Type Iii ◽  
Exchange Factor ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor

ABSTRACT We report the characterization of BopE, a type III secreted protein that is encoded adjacent to the Burkholderia pseudomallei bsa locus and is homologous to Salmonella enterica SopE/SopE2. Inactivation of bopE impaired bacterial entry into HeLa cells, indicating that BopE facilitates invasion. Consistent with this notion, BopE expressed in eukaryotic cells induced rearrangements in the subcortical actin cytoskeleton, and purified BopE exhibited guanine nucleotide exchange factor activity for Cdc42 and Rac1 in vitro.

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