The integral membrane S-locus receptor kinase of Brassica has serine/threonine kinase activity in a membranous environment and spontaneously forms oligomers in planta
AUTOR(ES)
Giranton, Jean-Loïc
FONTE
The National Academy of Sciences
RESUMO
To gain further insight into the mode of action of S-locus receptor kinase (SRK), a receptor-like kinase involved in the self-incompatibility response in Brassica, different recombinant SRK proteins have been expressed in a membranous environment using the insect cell/baculovirus system. Recombinant SRK proteins exhibited properties close to those of the endogenous stigmatic SRK protein and were found to autophosphorylate on serine and threonine residues in insect cell microsomes. Autophosphorylation was constitutive because it did not require the presence of pollen or stigma extracts in the phosphorylation buffer. Phosphorylation was shown to occur in trans, suggesting the existence of constitutive homooligomers of membrane-anchored recombinant SRK. To investigate the physiological relevance of these results, we have examined the oligomeric status of SRK in planta in cross-linking experiments and by velocity sedimentation on sucrose gradients. Our data strongly suggest that SRK is associated both with other SRK molecules and other stigma proteins in nonpollinated flowers. These findings may have important implications for our understanding of self-pollen signaling.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=16313Documentos Relacionados
- The S-locus receptor kinase gene in a self-incompatible Brassica napus line encodes a functional serine/threonine kinase.
- A plant receptor-like gene, the S-locus receptor kinase of Brassica oleracea L., encodes a functional serine/threonine kinase.
- Characterization of a Hank’s Type Serine/Threonine Kinase and Serine/Threonine Phosphoprotein Phosphatase in Pseudomonas aeruginosa
- Evidence for Serine/Threonine and Histidine Kinase Activity in the Tobacco Ethylene Receptor Protein NTHK21
- A tightly associated serine/threonine protein kinase regulates phosphoinositide 3-kinase activity.
