Role of threonine residues in the regulation of manganese-dependent arabidopsis serine/threonine/tyrosine protein kinase activity

2006 ◽  
Vol 455 (2) ◽  
pp. 99-109 ◽  
Author(s):  
Mamatha M. Reddy ◽  
Ram Rajasekharan
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Tyrosine Protein Kinase

scholarly journals Cks1 Is Required for G1Cyclin–Cyclin-Dependent Kinase Activity in Budding Yeast

2000 ◽  
Vol 20 (16) ◽  
pp. 5858-5864 ◽  
Author(s):  
Gregory J. Reynard ◽  
William Reynolds ◽  
Rati Verma ◽  
Raymond J. Deshaies
Keyword(s):  
Protein Kinase ◽  
Kinase Activity ◽  
Budding Yeast ◽  
Protein Kinase Activity ◽  
Cyclin Dependent Kinase ◽  
Multiple Substrates ◽  
Cell Extracts

ABSTRACT p13suc1 (Cks) proteins have been implicated in the regulation of cyclin-dependent kinase (CDK) activity. However, the mechanism by which Cks influences the function of cyclin-CDK complexes has remained elusive. We show here that Cks1 is required for the protein kinase activity of budding yeast G1 cyclin-CDK complexes. Cln2 and Cdc28 subunits coexpressed in baculovirus-infected insect cells fail to exhibit protein kinase activity towards multiple substrates in the absence of Cks1. Cks1 can both stabilize Cln2-Cdc28 complexes and activate intact complexes in vitro, suggesting that it plays multiple roles in the biogenesis of active G1cyclin-CDK complexes. In contrast, Cdc28 forms stable, active complexes with the B-type cyclins Clb4 and Clb5 regardless of whether Cks1 is present. The levels of Cln2-Cdc28 and Cln3-Cdc28 protein kinase activity are severely reduced in cks1-38 cell extracts. Moreover, phosphorylation of G1 cyclins, which depends on Cdc28 activity, is reduced in cks1-38 cells. The role of Cks1 in promoting G1 cyclin-CDK protein kinase activity both in vitro and in vivo provides a simple molecular rationale for the essential role of CKS1 in progression through G1 phase in budding yeast.

Diminished tyrosine protein kinase activity in T cells unresponsive to TCR stimulation

1994 ◽  
Vol 55 (3) ◽  
pp. 289-298 ◽  
Author(s):  
Alexander Y. Tsygankov ◽  
Ha W. Kim ◽  
Joanne C. Pratt ◽  
Carl Spana ◽  
Kenneth Class ◽  
...  
Keyword(s):  
T Cells ◽  
Protein Kinase ◽  
Kinase Activity ◽  
Protein Kinase Activity ◽  
Tyrosine Protein Kinase
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