Arabidopsis RecQsim, a plant-specific member of the RecQ helicase family, can suppress the MMS hypersensitivity of the yeast sgs1 mutant.
The Arabidopsis genome contains seven genes that belong to the RecQ family of ATP-dependent DNA helicases. RecQ members in Saccharomyces cerevisiae (SGS1) and man (WRN, BLM and RecQL4) are involved in DNA recombination, repair and genome stability maintenance, but little is known about the function of their plant counterparts. The Arabidopsis thaliana RecQsim gene is remarkably different from the other RecQ-like genes due to an insertion in its helicase domain. We isolated the AtRecQsim orthologues from rice and rape and established the presence of a similar insertion in their helicase domain, which suggests a plant specific function for the insert. The expression pattern of the AtRecQsim gene was compared with the other Arabidopsis RecQ-like members in different tissues and in response to stress. The transcripts of the AtRecQsim gene were found in all plant organs and its accumulation was higher in roots and seedlings, as compared to the other AtRecQ-like members. In contrast to most AtRecQ-like genes, the examined environmental cues did not have a detectable effect on the accumulation of the AtRecQsim transcripts. The budding yeast sgs1 mutant, which is known to be hypersensitive to the DNA-damaging drug MMS, was transformed with the AtRecQsim cDNA. The AtRecQsim gene suppressed the MMS hypersensitivity phenotype of the sgs1 cells. We propose that the Arabidopsis RecQsim gene, despite its unusual structure, exhibits an evolutionary conserved function.
Bagherieh-Najjar
Mohammad B
MB
Molecular Biology of Plants, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Kerklaan 30, 9751 NN Haren, The Netherlands.
de Vries
Onno M H
OM
Kroon
Johan T M
JT
Wright
Emma L
EL
Elborough
Kieran M
KM
Hille
Jacques
J
Dijkwel
Paul P
PP
D000040:Abscisic Acid / Q000494:pharmacology; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology / Q000235:genetics*; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D029688:Brassica napus / Q000201:enzymology / Q000235:genetics; D003080:Cold Temperature; D004265:DNA Helicases / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000528:radiation effects; D018506:Gene Expression Regulation, Plant / Q000187:drug effects / Q000528:radiation effects; D005816:Genetic Complementation Test; D008741:Methyl Methanesulfonate / Q000633:toxicity; D008969:Molecular Sequence Data; D009153:Mutagens / Q000633:toxicity; D009154:Mutation; D012275:Oryza / Q000201:enzymology / Q000235:genetics; D053484:RecQ Helicases; D012441:Saccharomyces cerevisiae / Q000187:drug effects / Q000201:enzymology / Q000235:genetics*; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D012965:Sodium Chloride / Q000494:pharmacology; D014466:Ultraviolet Rays
D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D009153:Mutagens; D029701:Saccharomyces cerevisiae Proteins; D012965:Sodium Chloride; D000040:Abscisic Acid; D008741:Methyl Methanesulfonate; C090472:SGS1 protein, S cerevisiae; D004265:DNA Helicases; D053484:RecQ Helicases; C476039:RecQsim protein, Arabidopsis