ANALYSIS OF TWO TYPE OF RPA70KDA SUBUNITS, RPA32KDA AND RPA14KDA SUBUNITS IN HIGHER PLANTS.

Abstract

RPA (Replication Protein A) has a multi-function protein involved in DNA replication, transcription, DNA repair, DNA recombination and so on. RPA is three subunits protein consists in 70kDa, 32kDa and 14kDa in human. We report cloning of two types of RPA70kDa subunit (OsRPA70a, b), RPA30kDa subunit (OsRPA32) and RPA14kDa subunit (OsRPA14) in rice (Oryza sativa). In animal and yeast, 70kDa subunit has just one type, but in plant, 70kDa subunit has two types. Two types of RPA70kDa subunit differ the expression tissues. OsRPA32 binds to OsRPA70b stronger than OsRPA70a. And T-DNA insertion line in Arabidopsis thalina RPA70a homologues is lethal, but theirs RPA70b homologues is not lethal. And AtRPA70b mutant is sensitive for UV and MMS. So, two types of RPA70kDa subunits may have different function in DNA repair mechanism.