Translesion synthesis past acrolein-derived DNA adduct, gamma -hydroxypropanodeoxyguanosine, by yeast and human DNA polymerase eta.

Abstract

gamma-Hydroxy-1,N(2)-propano-2'deoxyguanosine (gamma-HOPdG) is a major deoxyguanosine adduct derived from acrolein, a known mutagen. In vitro, this adduct has previously been shown to pose a severe block to translesion synthesis by a number of polymerases (pol). Here we show that both yeast and human pol eta can incorporate a C opposite gamma-HOPdG at approximately 190- and approximately 100-fold lower efficiency relative to the control deoxyguanosine and extend from a C paired with the adduct at approximately 8- and approximately 19-fold lower efficiency. Although DNA synthesis past gamma-HOPdG by yeast pol eta was relatively accurate, the human enzyme misincorporated nucleotides opposite the lesion with frequencies of approximately 10(-1) to 10(-2). Because gamma-HOPdG can adopt both ring closed and ring opened conformations, comparative replicative bypass studies were also performed with two model adducts, propanodeoxyguanosine and reduced gamma-HOPdG. For both yeast and human pol eta, the ring open reduced gamma-HOPdG adduct was less blocking than gamma-HOPdG, whereas the ring closed propanodeoxyguanosine adduct was a very strong block. Replication of DNAs containing gamma-HOPdG in wild type and xeroderma pigmentosum variant cells revealed a somewhat decreased mutation frequency in xeroderma pigmentosum variant cells. Collectively, the data suggest that pol eta might potentially contribute to both error-free and mutagenic bypass of gamma-HOPdG.

• Authors: Irina G Minko, M Todd Washington, Manorama Kanuri, Louise Prakash, Satya Prakash, R Stephen Lloyd
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 278 Issue 2 Pg. 784-90 (Jan 10 2003) ISSN: 0021-9258 [Print] United States
• PMID: 12401796 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• DNA Adducts
• Saccharomyces cerevisiae Proteins
• Acrolein
• DNA-Directed DNA Polymerase
• Deoxyguanosine
• DNA Polymerase iota
• POLI protein, human

Topics

• Acrolein (metabolism, toxicity)
• DNA Adducts (chemistry, metabolism)
• DNA Replication
• DNA-Directed DNA Polymerase (physiology)
• Deoxyguanosine (metabolism)
• Humans
• Saccharomyces cerevisiae Proteins (physiology)
• DNA Polymerase iota