Deactivation of the Arabidopsis BRASSINOSTEROID INSENSITIVE 1 (BRI1) receptor kinase by autophosphorylation within the glycine-rich loop.

ABSTRACT: The activity of the dual-specificity receptor kinase, brassinosteroid insensitive 1 (BRI1), reflects the balance between phosphorylation-dependent activation and several potential mechanisms for deactivation of the receptor. In the present report, we elucidate a unique mechanism for deactivation that involves autophosphorylation of serine-891 in the ATP-binding domain. Serine-891 was identified previously as a potential site of autophosphorylation by mass spectrometry, and sequence-specific antibodies and mutagenesis studies now unambiguously establish phosphorylation of this residue. In vivo, phosphorylation of serine-891 increased slowly with time following application of brassinolide (BL) to Arabidopsis seedlings, whereas phosphorylation of threonine residues increased rapidly and then

SUBMITTER: Oh MH 

PROVIDER: S-EPMC3252896 | biostudies-literature | 2012 Jan

REPOSITORIES: biostudies-literature