Physical and functional interactions of human DNA polymerase eta with PCNA.
Human DNA polymerase eta (hPoleta) functions in the error-free replication of UV-damaged DNA, and mutations in hPoleta cause cancer-prone syndrome, the variant form of xeroderma pigmentosum. However, in spite of its key role in promoting replication through a variety of distorting DNA lesions, the manner by which hPoleta is targeted to the replication machinery stalled at a lesion site remains unknown. Here, we provide evidence for the physical interaction of hPoleta with proliferating cell nuclear antigen (PCNA) and show that mutations in the PCNA binding motif of hPoleta inactivate this interaction. PCNA, together with replication factor C and replication protein A, stimulates the DNA synthetic activity of hPoleta, and steady-state kinetic studies indicate that this stimulation accrues from an increase in the efficiency of nucleotide insertion resulting from a reduction in the apparent K(m) for the incoming nucleotide.
Haracska
L
L
Sealy Center for Molecular Science, University of Texas Medical Branch, Galveston, Texas 77555-1061, USA.
Johnson
R E
RE
Unk
I
I
Phillips
B
B
Hurwitz
J
J
Prakash
L
L
Prakash
S
S
D000595:Amino Acid Sequence; D004249:DNA Damage; D004260:DNA Repair; D004268:DNA-Binding Proteins / Q000378:metabolism; D004259:DNA-Directed DNA Polymerase / Q000737:chemistry* / Q000378:metabolism*; D006801:Humans; D007700:Kinetics; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D018809:Proliferating Cell Nuclear Antigen / Q000737:chemistry* / Q000378:metabolism*; D011485:Protein Binding; D051716:Replication Protein A; D051818:Replication Protein C; D017386:Sequence Homology, Amino Acid; D020798:Two-Hybrid System Techniques; D014466:Ultraviolet Rays; D000099270:Y-Family DNA Polymerases
D004268:DNA-Binding Proteins; D004259:DNA-Directed DNA Polymerase; D018809:Proliferating Cell Nuclear Antigen; D051716:Replication Protein A; D051818:Replication Protein C; C497167:RPA1 protein, human; C112338:Rad30 protein; D000099270:Y-Family DNA Polymerases