TY - JOUR
T1 - MCM3-binding GANP DNA-primase is associated with a novel phosphatase component G5PR
AU - Kono, Yoshihiko
AU - Maeda, Kazuhiko
AU - Kuwahara, Kazuhiko
AU - Yamamoto, Hideyuki
AU - Miyamoto, Eishichi
AU - Yonezawa, Kazuyoshi
AU - Takagi, Katsumasa
AU - Sakaguchi, Nobuo
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2002/8
Y1 - 2002/8
N2 - Background: GANP, carrying DNA-primase and MCM3-binding domains, is up-regulated in germinal centre B cells. To understand the regulatory function of GANP upon MCM complex, we searched for GANP-associated molecules by yeast two-hybrid screening. Results: Using the 1 kb fragment (G5) of the ganp cDNA, we identified a clone named G5PR that is structurally homologous to known regulatory subunits of protein phosphatases (PPases) and determined the association of G5PR with GANP in vivo in the DNA transfectant. G5PR is associated with protein phosphatase 5 (PP5) through its tetratricopeptide-repeat (TPR) domain. Pull-down assays demonstrated that G5PR is also associated with protein phosphatase 2A (PP2A), the complex of A subunit (PR65) and the catalytic (C) subunit (PP2Ac), similar to the B″ subunit. The G5PR-associated complex had phosphatase activity on casein, histone H1 and MCM3 in vitro, but the addition of G5PR did not stimulate or inhibit the phosphatase activities of PP5 and PP2A. The cellular localization of G5PR in transfected cells varies during cell cycling, appearing in the nucleus during prophase, in the peri-chromatin during mitotic phase, and in the cytoplasm after cell division. Conclusion: G5PR is capable of recruiting two kinds of PPases, PP5 and PP2A, into the GANP/MCM3 complex, which might regulate its phosphorylation state during cell cycle progression.
AB - Background: GANP, carrying DNA-primase and MCM3-binding domains, is up-regulated in germinal centre B cells. To understand the regulatory function of GANP upon MCM complex, we searched for GANP-associated molecules by yeast two-hybrid screening. Results: Using the 1 kb fragment (G5) of the ganp cDNA, we identified a clone named G5PR that is structurally homologous to known regulatory subunits of protein phosphatases (PPases) and determined the association of G5PR with GANP in vivo in the DNA transfectant. G5PR is associated with protein phosphatase 5 (PP5) through its tetratricopeptide-repeat (TPR) domain. Pull-down assays demonstrated that G5PR is also associated with protein phosphatase 2A (PP2A), the complex of A subunit (PR65) and the catalytic (C) subunit (PP2Ac), similar to the B″ subunit. The G5PR-associated complex had phosphatase activity on casein, histone H1 and MCM3 in vitro, but the addition of G5PR did not stimulate or inhibit the phosphatase activities of PP5 and PP2A. The cellular localization of G5PR in transfected cells varies during cell cycling, appearing in the nucleus during prophase, in the peri-chromatin during mitotic phase, and in the cytoplasm after cell division. Conclusion: G5PR is capable of recruiting two kinds of PPases, PP5 and PP2A, into the GANP/MCM3 complex, which might regulate its phosphorylation state during cell cycle progression.
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U2 - 10.1046/j.1365-2443.2002.00562.x
DO - 10.1046/j.1365-2443.2002.00562.x
M3 - Article
C2 - 12167160
AN - SCOPUS:0036668467
VL - 7
SP - 821
EP - 834
JO - Genes to Cells
JF - Genes to Cells
SN - 1356-9597
IS - 8
ER -