Oligomerization studies show that the kinase domain of the tomato pollen receptor kinase LePRK2 is necessary for interaction with LePRK1.
LePRK1 and LePRK2 are two pollen-specific receptor-like kinases from Solanum lycopersicum that are involved in signaling during pollen-pistil communication. Previously, we showed that both proteins interact in pollen and when expressed in yeast. We also showed that pollen tube length was regulated by phosphorylation of specific residues in the juxtamembrane domain of LePRK2. To determine the domains responsible for the interaction between LePRK1 and LePRK2, we constructed a series of deletions, expressed them in yeast and determined their association by co-immunoprecipitation assays. We show that deletions containing extracellular domains of LePRK1 and LePRK2 were glycosylated in yeast and were sufficient for interaction with the corresponding full-length receptor. The juxtamembrane domain of LePRK1 was sufficient for its interaction with LePRK2, whereas LePRK2 required its kinase domain for interaction with LePRK1. These findings suggest a role for the juxtamembrane domain of LePRK2 in mediating intracellular dimerization and thus receptor kinase phosphorylation.
Instituto de Ingeniería Genética y Biología Molecular INGEBI - Consejo Nacional de Investigaciones Científicas y Técnicas, 1428 Buenos Aires, Argentina.
Tamara Marcela
TM
Salem
María Laura
ML
Barberini
Diego Leonardo
DL
Wengier
María Laura
ML
Cabanas
Pablo
P
de Paz
Jorge
J
Muschietti
D019281:Dimerization; D006031:Glycosylation; D047468:Immunoprecipitation; D018551:Solanum lycopersicum / Q000378:metabolism*; D009154:Mutation; D010766:Phosphorylation; D010940:Plant Proteins / Q000378:metabolism*; D011058:Pollen / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D015398:Signal Transduction; D013379:Substrate Specificity; D015003:Yeasts / Q000235:genetics
D010940:Plant Proteins; C061570:protein kinase N; D011493:Protein Kinase C