Allele-specific receptor-ligand interactions in Brassica self-incompatibility.
Genetic self-incompatibility in Brassica is determined by alleles of the transmembrane serine-threonine kinase SRK, which functions in the stigma epidermis, and of the cysteine-rich peptide SCR, which functions in pollen. Using tagged versions of SRK and SCR as well as endogenous stigma and pollen proteins, we show that SCR binds the SRK ectodomain and that this binding is allele specific. Thus, SRK and SCR function as a receptor-ligand pair in the recognition of self pollen. Specificity in the self-incompatibility response derives from allele-specific formation of SRK-SCR complexes at the pollen-stigma interface.
Kachroo
A
A
Department of Plant Biology, Cornell University, Ithaca, NY 14853, USA.
Schopfer
C R
CR
Nasrallah
M E
ME
Nasrallah
J B
JB
D000483:Alleles; D001665:Binding Sites; D001937:Brassica / Q000235:genetics* / Q000378:metabolism*; D005306:Fertilization / Q000502:physiology; D008024:Ligands; D010940:Plant Proteins / Q000235:genetics / Q000378:metabolism*; D018514:Plant Structures / Q000378:metabolism*; D030821:Plants, Genetically Modified; D010947:Plants, Toxic; D011058:Pollen / Q000378:metabolism*; D011485:Protein Binding; D011494:Protein Kinases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D013045:Species Specificity; D013379:Substrate Specificity; D014026:Nicotiana
D008024:Ligands; D010940:Plant Proteins; D011993:Recombinant Fusion Proteins; C401308:SCR protein, Brassica oleracea; D011494:Protein Kinases; C079832:S-receptor kinase