The second subunit of the replication factor C complex (RFC40) and the regulatory subunit (RIalpha) of protein kinase A form a protein complex promoting cell survival.
Replication Factor C (RFC) is required for the loading of Proliferating Cell Nuclear Antigen (PCNA) onto DNA during DNA replication, repair and recombination. RFC40, the second subunit of the RFC complex, and PCNA have been shown to be overexpressed in gestational trophoblastic diseases. Using RFC40 as the bait in a yeast two-hybrid screening, we have identified a novel interaction between RFC40 and the regulatory subunit (RIalpha) of cAMP-dependent Protein kinase A (PKA). The interaction sites between these two proteins were investigated and mapped to the N-terminus of RIalpha and the C-terminus of RFC40. Moreover, it was demonstrated that the C-subunit of PKA was not associated with the RFC40-RIalpha complex. Furthermore, RFC37, the third subunit of the RFC complex, competes with RIalpha and displaces it from the RFC40-RIalpha complex. Interestingly, downregulation of endogenous RIalpha by 8-chloro cAMP, in MCF7 breast cancer cells led to reduction in the amount of RFC40-RIalpha complex, together with decrease in cell survival.
Gupte
Rakhee S
RS
Department of Biochemistry and Molecular Biology, New York Medical College, Valhalla, New York 10595, USA.
Weng
Yun
Y
Liu
Li
L
Lee
Marietta Y W T
MY
D015124:8-Bromo Cyclic Adenosine Monophosphate / Q000031:analogs & derivatives / Q000494:pharmacology; D002460:Cell Line; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000235:genetics / Q000502:physiology*; D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; D017868:Cyclic AMP-Dependent Protein Kinases / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D015536:Down-Regulation / Q000187:drug effects; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D006801:Humans; D015151:Immunoblotting; D047468:Immunoprecipitation; D046912:Multiprotein Complexes / Q000737:chemistry / Q000235:genetics / Q000502:physiology*; D025941:Protein Interaction Mapping; D051818:Replication Protein C / Q000737:chemistry* / Q000235:genetics / Q000502:physiology*; D020798:Two-Hybrid System Techniques
D054756:Cyclic AMP-Dependent Protein Kinase RIalpha Subunit; D046912:Multiprotein Complexes; C517834:PRKAR1A protein, human; D015124:8-Bromo Cyclic Adenosine Monophosphate; C044258:8-chloro-cyclic adenosine monophosphate; D017868:Cyclic AMP-Dependent Protein Kinases; D051818:Replication Protein C