Subcellular localization and functions of the barley stem rust resistance receptor-like serine/threonine-specific protein kinase Rpg1.

ABSTRACT: The Rpg1 gene confers resistance to many pathotypes of the stem rust fungus Puccinia graminis f. sp. tritici and has protected barley from serious disease losses for over 60 years. Rpg1 encodes a constitutively expressed protein with two tandem kinase domains. Fractionation by differential centrifugation and aqueous two-phase separation of the microsome proteins located Rpg1 mainly in the cytosol but also in the plasma membrane and intracellular membranes. Recombinant Rpg1 autophosphorylates in vitro intramolecularly only serine and threonine amino acids with a preference for Mn(2+) cations and a K(m) of 0.15 and a V(max) of 0.47 nmol.min(-1).mg(-1) protein. The inability of wild-type Rpg1 to transphosphorylate a recombinant Rpg1 inactivated by site-directed mutation confirmed that Rpg1 au

SUBMITTER: Nirmala J 

PROVIDER: S-EPMC1464370 | biostudies-literature | 2006 May

REPOSITORIES: biostudies-literature