This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Vollberg, T. M. Articles by Sirover, M. A. Search for Related Content PubMed PubMed Citation Articles by Vollberg, T. M. Articles by Sirover, M. A.

Biosynthesis of the Human Base Excision Repair Enzyme Uracil-DNA Glycosylase¹

Fels Research Institute and the Department of Pharmacology, Temple University School of Medicine, Philadelphia, Pennsylvania 19140

The biosynthesis of the human DNA repair enzyme uracil-DNA glycosylase has been characterized by the reaction of in vitro- and in vivo-produced protein with an anti-human placental uracil-DNA glycosylase monoclonal antibody. In vitro synthesis of the DNA repair enzyme was examined after the translation of human placental polyadenylated [poly(A)⁺] RNA by immunoprecipitation of the [³⁵S]methionine-labeled translation products. As defined by sucrose density analysis, immunoprecipitable in vitro products were translated from 16S poly(A)⁺ RNA and 11S poly(A)⁺ RNA. While the products of the 11S poly(A)⁺ RNA were smaller than purified uracil-DNA glycosylase, the product of the 16 S poly(A)⁺ RNA had a molecular weight of 37,000, identical to the size previously observed for purified human placental uracil-DNA glycosylase. Immunoblot analysis of human placental cell extracts and of normal human fibroblast cell extracts demonstrated the recognition of one M_r 37,000 protein. Immunoprecipitation of [³⁵S]methionine-labeled normal human cell extracts with the anti-glycosylase monoclonal antibody specifically detected only the M_r 37,000 uracil-DNA glycosylase protein. Pulse-chase analysis demonstrated that the ³⁵S radioactivity in the M_r 37,000 uracil-DNA glycosylase decreased over a 5-h interval. These results show that immunoreactive human uracil-DNA glycosylase protein was synthesized at its enzymatically active molecular weight of 37,000 as the primary translation product of a 16S polyadenylated messenger RNA.

¹ This study was supported by a grant to M. A. S. from the NIH (CA-29414) and by grants to the Fels Research Institute from the NIH (CA-12227) and from the American Cancer Society (SIG-6).

² To whom requests for reprints should be addressed.

Received 2/18/86. Revised 7/24/86. Revised 9/17/86. Accepted 9/24/86.