TY - JOUR
T1 - DP1 phosphorylation in multimeric complexes
T2 - Weaker interaction with cyclin A through the E2F1 cyclin A binding domain leads to more efficient phosphorylation than stronger interaction through the p107 cyclin A binding domain
AU - Guida, Peter
AU - Zhu, Liang
N1 - Funding Information:
We thank Doron Ginsberg, Wilhelm Krek and David Livingston; Sander van den Heuvel and Ed Harlow; Philip Hinds and Robert Weinberg; and Richard Pestell for various reagents used in this study, and Anthony Karnezis for critical reading of the manuscript. We also thank the Pestell lab for assistance with luciferase assays. This work was supported by an American Cancer Society Research Project Grant 97-125-01. The Albert Einstein Cancer Center core support is also acknowledged. P.G. was supported by an NIH Cell and Molecular Biology Training Grant and L.Z. is a Leukemia Society of America Scholar.
PY - 1999/5/19
Y1 - 1999/5/19
N2 - Stable enzyme-substrate interaction has been recognized as a major mechanism underlying the substrate preferences of cyclin-dependent kinases (Cdks). To learn the relationship between stability of physical association and efficiency of phosphorylation, we studied DP1 phosphorylation by cyclin A-Cdk2 in multiprotein complexes. When DP1 was connected to cyclin A-Cdk2 through E2F4 and p107, its phosphorylation was very inefficient, although its association with cyclin A-Cdk2 was stable. In contrast, DP1 was efficiently phosphorylated when weakly connected to cyclin A-Cdk2 via E2F1 or E2F4 with a fused cyclin A binding domain of E2F1. The transactivation activity of E2F4-DP1 heterodimers was reduced when DP1 was phosphorylated, while a phosphorylation deficient mutant of DP1 resisted this down-regulation. Phosphorylation and functional regulation of DP1 were not due to nuclear localization. Thus, stronger physical association between the kinase and the substrate does not necessarily lead to more efficient phosphorylation than weaker interaction does.
AB - Stable enzyme-substrate interaction has been recognized as a major mechanism underlying the substrate preferences of cyclin-dependent kinases (Cdks). To learn the relationship between stability of physical association and efficiency of phosphorylation, we studied DP1 phosphorylation by cyclin A-Cdk2 in multiprotein complexes. When DP1 was connected to cyclin A-Cdk2 through E2F4 and p107, its phosphorylation was very inefficient, although its association with cyclin A-Cdk2 was stable. In contrast, DP1 was efficiently phosphorylated when weakly connected to cyclin A-Cdk2 via E2F1 or E2F4 with a fused cyclin A binding domain of E2F1. The transactivation activity of E2F4-DP1 heterodimers was reduced when DP1 was phosphorylated, while a phosphorylation deficient mutant of DP1 resisted this down-regulation. Phosphorylation and functional regulation of DP1 were not due to nuclear localization. Thus, stronger physical association between the kinase and the substrate does not necessarily lead to more efficient phosphorylation than weaker interaction does.
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U2 - 10.1006/bbrc.1999.0656
DO - 10.1006/bbrc.1999.0656
M3 - Article
C2 - 10329431
AN - SCOPUS:0033583768
SN - 0006-291X
VL - 258
SP - 596
EP - 604
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 3
ER -