Human SHPRH is a ubiquitin ligase for Mms2-Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen.
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Unk I, Hajdu I, Fatyol K, Szakal B, Blastyak A, Bermudez V, Hurwitz J, Prakash L, Prakash S, Haracska L
Human SHPRH is a ubiquitin ligase for Mms2-Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen.
Proc Natl Acad Sci U S A. 2006 Nov 28;103(48):18107-12. Epub 2006 Nov 15.
- PubMed ID
- 17108083 [ View in PubMed]
- Abstract
Human SHPRH gene is located at the 6q24 chromosomal region, and loss of heterozygosity in this region is seen in a wide variety of cancers. SHPRH is a member of the SWI/SNF family of ATPases/helicases, and it possesses a C(3)HC(4) RING motif characteristic of ubiquitin ligase proteins. In both of these features, SHPRH resembles the yeast Rad5 protein, which, together with Mms2-Ubc13, promotes replication through DNA lesions via an error-free postreplicational repair pathway. Genetic evidence in yeast has indicated a role for Rad5 as a ubiquitin ligase in mediating the Mms2-Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen. Here we show that SHPRH is a functional homolog of Rad5. Similar to Rad5, SHPRH physically interacts with the Rad6-Rad18 and Mms2-Ubc13 complexes, and we show that SHPRH protein is a ubiquitin ligase indispensable for Mms2-Ubc13-dependent polyubiquitylation of proliferating cell nuclear antigen. Based on these observations, we predict a role for SHPRH in promoting error-free replication through DNA lesions. Such a role for SHPRH is consistent with the observation that this gene is mutated in a number of cancer cell lines, including those from melanomas and ovarian cancers, which raises the strong possibility that SHPRH function is an important deterrent to mutagenesis and carcinogenesis in humans.