Molecular cloning of a putative receptor protein kinase gene encoded at the self-incompatibility locus of Brassica oleracea.
Self-recognition between pollen and stigma during pollination in Brassica oleracea is genetically controlled by the multiallelic self-incompatibility locus (S). We describe the S receptor kinase (SRK) gene, a previously uncharacterized gene that resides at the S locus. The nucleotide sequences of genomic DNA and of cDNAs corresponding to SRK predict a putative transmembrane receptor having serine/threonine-specific protein kinase activity. Its extracellular domain exhibits striking homology to the secreted product of the S-locus glycoprotein (SLG) gene and is connected via a single pass transmembrane domain to a protein kinase catalytic center. SRK alleles derived from different S-locus genotypes are highly polymorphic and have apparently evolved in unison with genetically linked alleles of SLG. SRK directs the synthesis of several alternative transcripts, which potentially encode different protein products, and these transcripts were detected exclusively in reproductive organs. The identification of SRK may provide new perspectives into the signal transduction mechanism underlying pollen recognition.
Division of Biological Sciences, Cornell University, Ithaca, NY 14853.
J C
JC
Stein
B
B
Howlett
D C
DC
Boyes
M E
ME
Nasrallah
J B
JB
Nasrallah
D000483:Alleles; D000595:Amino Acid Sequence; D001483:Base Sequence; D015152:Blotting, Northern; D001937:Brassica / Q000235:genetics / Q000502:physiology*; D003001:Cloning, Molecular; D015870:Gene Expression; D017343:Genes, Plant; D008969:Molecular Sequence Data; D009841:Oligonucleotides / Q000737:chemistry; D011058:Pollen / Q000502:physiology; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D011505:Protein-Tyrosine Kinases / Q000235:genetics*; D012333:RNA, Messenger / Q000235:genetics; D011956:Receptors, Cell Surface / Q000235:genetics*; D015183:Restriction Mapping
D009841:Oligonucleotides; D012333:RNA, Messenger; D011956:Receptors, Cell Surface; D011505:Protein-Tyrosine Kinases