Stein J C, Howlett B, Boyes D C, Nasrallah M E, Nasrallah J B
Division of Biological Sciences, Cornell University, Ithaca, NY 14853.
Proc Natl Acad Sci U S A. 1991 Oct 1;88(19):8816-20. doi: 10.1073/pnas.88.19.8816.
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.
甘蓝授粉过程中花粉与柱头之间的自我识别受多等位基因自交不亲和位点(S)的遗传控制。我们描述了S受体激酶(SRK)基因,这是一个先前未被鉴定的位于S位点的基因。对应于SRK的基因组DNA和cDNA的核苷酸序列预测了一个具有丝氨酸/苏氨酸特异性蛋白激酶活性的推定跨膜受体。其细胞外结构域与S位点糖蛋白(SLG)基因的分泌产物具有显著同源性,并通过单次跨膜结构域连接到蛋白激酶催化中心。源自不同S位点基因型的SRK等位基因高度多态,并且显然与SLG的遗传连锁等位基因协同进化。SRK指导几种可变转录本的合成,这些转录本可能编码不同的蛋白质产物,并且这些转录本仅在生殖器官中被检测到。SRK的鉴定可能为花粉识别的信号转导机制提供新的视角。