The DNA Polymerase Activity ofSaccharomyces cerevisiaeRev1 is Biologically Significant

Abstract

A cell's ability to tolerate DNA damage is directly connected to the human development of diseases and cancer. To better understand the processes underlying mutagenesis, we studied the cell's reliance on the potentially error-prone translesion synthesis (TLS), and an error-free, template-switching pathway in Saccharomyces cerevisiae. The primary proteins mediating S. cerevisiae TLS are three DNA polymerases (Pols): Rev1, Pol z (Rev3/7), and Pol h (Rad30), all with human homologs. Rev1's noncatalytic role in recruiting other DNA polymerases is known to be important for TLS. However, the biological significance of Rev1's unusual conserved DNA polymerase activity, which inserts dC, is much less well understood. Here, we demonstrate that inactivating Rev1's DNA polymerase function sensitizes cells to both chronic and acute exposure to 4-nitroquinoline-1-oxide (4-NQO) but not to UV or cisplatin. Full Rev1-dependent resistance to 4-NQO, however, also requires the additional Rev1 functions. When error-free tolerance is disrupted through deletion of MMS2, Rev1's catalytic activity is more vital for 4-NQO resistance, possibly explaining why the biological significance of Rev1's catalytic activity has been elusive. In the presence or absence of Mms2-dependent error-free tolerance, the catalytic dead strain of Rev1 exhibits a lower 4-NQO-induced mutation frequency than wild type. Furthermore, Pol z, but not Pol h, also contributes to 4-NQO resistance. These results show that Rev1's catalytic activity is important in vivo when the cell has to cope with specific DNA lesions, such as N 2 -dG.

The Vital Role of Polymerase ζ and REV1 in Mutagenic, but Not Correct, DNA Synthesis across Benzo[a]pyrene-dG and Recruitment of Polymerase ζ by REV1 to Replication-stalled Site

“…Role for REV1 in TLS-Among the TLS-specialized DNA polymerases, REV1 plays a unique role in TLS by serving as a protein platform (40) although its deoxycytidyl transferase activity plays a role for TLS past some lesions (10,11). It is generally thought that REV1 and pol function together during TLS.…”

“…REV1, another member of the Y family, does not have a canonical DNA polymerase activity but instead shows a deoxycytidyl transferase activity (8,9). This enzyme activity plays a role in TLS across certain classes of lesions (10,11). REV1 also plays a noncatalytic role in TLS (12) and physically interacts with the other Y family polymerases (13,14) and the REV7 subunit of pol (15,16).…”

Stalled Polη at its cognate substrate initiates an alternative translesion synthesis pathway via interaction with REV1

“…6). Indeed, it has been reported that the Rev1¢s noncatalytic role was biologically significant for UV resistance in yeast (Wiltrout & Walker 2011).…”

1H, 13C, and 15N backbone resonance assignments of the full-length 40 kDa S. acidocaldarius Y-family DNA polymerase, dinB homolog

“…Dbh belongs to the Y-family of translesion (TLS) DNA polymerases that can accurately bypass a variety of damaged DNA templates (Yang and Woodgate 2007). Members of the Y-family include Dpo4 from Sulfolobus solfataricus, pol IV [E. coli, (Wagner et al 1999)] mammalian pol j (Ogi et al 1999;Ohashi et al 2000;Gerlach et al 2001), pol g (Johnson et al 1999a, b), pol i (McDonald et al 1999;Tissier et al 2000), and Rev1 (Lin et al 1999;Wiltrout and Walker 2011). In particular, Dbh shares 54 % sequence identity to Dpo4.…”