TY - JOUR
T1 - Cell cycle-dependent localization of the CDK2-cyclin E complex in Cajal (coiled) bodies
AU - Liu, Juinn Lin
AU - Hebert, Michael D.
AU - Ye, Ying
AU - Templeton, Dennis J.
AU - Kung, Hsing Jien
AU - Matera, A. Gregory
PY - 2000/6/5
Y1 - 2000/6/5
N2 - We have found that CDK2 and cyclin E, but not cyclin A, accumulates within Cajal bodies (CBs) in a cell cycle-dependent fashion. In the absence of cyclin E, CDK2 is not enriched in the CB compartment, suggesting that the translocation of CDK2 to CBs is dependent on cyclin E. CDK2 and cyclin E could be recruited to CBs as a functional complex or CBs may serve as 'docking stations' for CDK2-cyclin E activation by CAKs during the G1/S transition. Notably, CDK7-cyclin H-Mat1 complexes are known to accumulate in CBs. Treatment of cells with inhibitors of either CDKs (olomoucine, 200 μM) or RNA polymerase I (actinomycin D, 0.05 μg/ml), results in a striking reorganization of CDK2 and p80 coilin to the nucleolar periphery. Furthermore, we demonstrate that p80 coilin can be phosphorylated by purified CDK2-cyclin E complexes in vitro. Thus coilin and other CB proteins appear to be downstream targets of CDK2-cyclin E complex-mediated signaling pathways regulating cell cycle progression and controlling aspects of CB function. Possible roles for CDK2 and cyclin E in the well-documented association of CBs, histone gene clusters and RNA 3' end processing factors are discussed.
AB - We have found that CDK2 and cyclin E, but not cyclin A, accumulates within Cajal bodies (CBs) in a cell cycle-dependent fashion. In the absence of cyclin E, CDK2 is not enriched in the CB compartment, suggesting that the translocation of CDK2 to CBs is dependent on cyclin E. CDK2 and cyclin E could be recruited to CBs as a functional complex or CBs may serve as 'docking stations' for CDK2-cyclin E activation by CAKs during the G1/S transition. Notably, CDK7-cyclin H-Mat1 complexes are known to accumulate in CBs. Treatment of cells with inhibitors of either CDKs (olomoucine, 200 μM) or RNA polymerase I (actinomycin D, 0.05 μg/ml), results in a striking reorganization of CDK2 and p80 coilin to the nucleolar periphery. Furthermore, we demonstrate that p80 coilin can be phosphorylated by purified CDK2-cyclin E complexes in vitro. Thus coilin and other CB proteins appear to be downstream targets of CDK2-cyclin E complex-mediated signaling pathways regulating cell cycle progression and controlling aspects of CB function. Possible roles for CDK2 and cyclin E in the well-documented association of CBs, histone gene clusters and RNA 3' end processing factors are discussed.
KW - CDK2
KW - Coiled body
KW - Cyclin
KW - Nucleolus
KW - Transformation
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UR - http://www.scopus.com/inward/citedby.url?scp=0034110119&partnerID=8YFLogxK
U2 - 10.1242/jcs.113.9.1543
DO - 10.1242/jcs.113.9.1543
M3 - Article
C2 - 10751146
AN - SCOPUS:0034110119
SN - 0021-9533
VL - 113
SP - 1543
EP - 1552
JO - Journal of Cell Science
JF - Journal of Cell Science
IS - 9
ER -