Roles of PCNA-binding and ubiquitin-binding domains in human DNA polymerase eta in translesion DNA synthesis.
Treatment of yeast and human cells with DNA-damaging agents elicits Rad6-Rad18-mediated monoubiquitination of proliferating cell nuclear antigen (PCNA) at its Lys-164 residue [ubiquitin (Ub)-PCNA], and this PCNA modification is indispensable for promoting the access of translesion synthesis (TLS) polymerases (Pols) to PCNA. However, the means by which K164-linked Ub modulates the proficiency of TLS Pols to bind PCNA and take over synthesis from the replicative Pol has remained unclear. One model that has gained considerable credence is that the TLS Pols bind PCNA at 2 sites, to the interdomain connector loop via their PCNA-interacting protein (PIP) domain and to the K164-linked Ub moiety via their Ub-binding domain (UBD). Specifically, this model postulates that the UBD-mediated binding of TLS Pols to the Ub moiety on PCNA is necessary for TLS. To test the validity of this model, we examine the contributions that the PIP and Ub-binding zinc finger (UBZ) domains of human Poleta make to its functional interaction with PCNA, its colocalization with PCNA in replication foci, and its role in TLS in vivo. We conclude from these studies that the binding to PCNA via its PIP domain is a prerequisite for Poleta's ability to function in TLS in human cells and that the direct binding of the Ub moiety on PCNA via its UBZ domain is not required. We discuss the possible role of the Ub moiety on PCNA in TLS.
Acharya
Narottam
N
Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, 301 University Boulevard, Galveston, TX 77555-1061, USA.
Yoon
Jung-Hoon
JH
Gali
Himabindu
H
Unk
Ildiko
I
Haracska
Lajos
L
Johnson
Robert E
RE
Hurwitz
Jerard
J
Prakash
Louise
L
Prakash
Satya
S
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D004247:DNA / Q000096:biosynthesis*; D004252:DNA Mutational Analysis; D004261:DNA Replication; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D050505:Mutant Proteins / Q000737:chemistry / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D018809:Proliferating Cell Nuclear Antigen / Q000378:metabolism*; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D013329:Structure-Activity Relationship; D025801:Ubiquitin / Q000378:metabolism*; D000099270:Y-Family DNA Polymerases
D004247:DNA; D004259:DNA-Directed DNA Polymerase; D050505:Mutant Proteins; D018809:Proliferating Cell Nuclear Antigen; D025801:Ubiquitin; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases