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Cell cycle-specific UNG2 phosphorylations regulate protein turnover, activity and association with RPA.

Authors :
Hagen, Lars
Kavli, Bodil
Sousa, Mirta M. L.
Torseth, Kathrin
Liabakk, Nina B.
Sundheim, Ottar
Peňa-Diaz, Javier
Otterlei, Marit
Hørning, Ole
Jensen, Ole N.
Krokan, Hans E.
Slupphaug, Geir
Source :
EMBO Journal; 1/9/2008, Vol. 27 Issue 1, p51-61, 11p, 1 Black and White Photograph, 1 Diagram, 1 Chart, 3 Graphs
Publication Year :
2008

Abstract

Human UNG2 is a multifunctional glycosylase that removes uracil near replication forks and in non-replicating DNA, and is important for affinity maturation of antibodies in B cells. How these diverse functions are regulated remains obscure. Here, we report three new phosphoforms of the non-catalytic domain that confer distinct functional properties to UNG2. These are apparently generated by cyclin-dependent kinases through stepwise phosphorylation of S23, T60 and S64 in the cell cycle. Phosphorylation of S23 in late G1/early S confers increased association with replication protein A (RPA) and replicating chromatin and markedly increases the catalytic turnover of UNG2. Conversely, progressive phosphorylation of T60 and S64 throughout S phase mediates reduced binding to RPA and flag UNG2 for breakdown in G2 by forming a cyclin E/c-myc-like phosphodegron. The enhanced catalytic turnover of UNG2 p-S23 likely optimises the protein to excise uracil along with rapidly moving replication forks. Our findings may aid further studies of how UNG2 initiates mutagenic rather than repair processing of activation-induced deaminase-generated uracil at Ig loci in B cells. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
02614189
Volume :
27
Issue :
1
Database :
Complementary Index
Journal :
EMBO Journal
Publication Type :
Academic Journal
Accession number :
28154614
Full Text :
https://doi.org/10.1038/sj.emboj.7601958