Report

Molecular Mechanism for Plant Steroid Receptor Activation by Somatic Embryogenesis Co-Receptor Kinases

See allHide authors and affiliations

Science  08 Aug 2013:
1242468
DOI: 10.1126/science.1242468

You are currently viewing the abstract.

View Full Text

Log in to view the full text

Log in through your institution

Log in through your institution

Abstract

Brassinosteroids (BRs) control plant growth and development. BRs are sensed by the leucine-rich repeat (LRR) domain of the membrane receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1), but it is unknown how steroid binding at the cell surface activates the cytoplasmic kinase domain of the receptor. A family of somatic embryogenesis receptor kinases (SERKs) has been genetically implicated in mediating early BR-signaling events. Here, we present evidence for a direct and steroid-dependent interaction between the BRI1 and SERK1 LRR domains by analysis of their complex crystal structure at 3.3 Å resolution. We show that the SERK1 LRR domain is involved in steroid sensing and, through receptor-co-receptor heteromerisation, in the activation of the BRI1 signaling pathway. Our work rationalizes the effects of known mis-sense mutations in BRI1 and in SERKs and the targeting mechanism of BRI1 receptor antagonists.

View Full Text