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Query: UMLS:C0277787 (stigma)
 13,352 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The protein kinase family of enzymes mediates the responses of eukaryotic cells to both inter- and intracellular signals. These enzymes are either serine/threonine-specific or tyrosine-specific. Many of the latter are transmembrane receptors and are important in transduction of extracellular signals across the plasma membrane, whereas few examples of receptor serine kinases have been reported. We have now identified a complementary DNA clone from Zea mays (L.) encoding a putative serine/threonine-specific protein kinase structurally related to the receptor tyrosine kinases. This structural similarity is evidence for a previously undescribed class of transmembrane receptor in higher plants likely to be involved in signal reception and transduction. Furthermore, the catalytic domain of this protein kinase is linked through a transmembrane domain to an extracellular domain similar to that of glycoproteins encoded in the self-incompatibility locus of Brassica which are involved in the self-recognition system between pollen and stigma.
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PMID:Relationship of a putative receptor protein kinase from maize to the S-locus glycoproteins of Brassica. 216 28

ARK1 is a vegetatively expressed receptor protein kinase gene isolated from Arabidopsis thaliana based on its sequence similarity to Brassica genes involved in pollen-stigma signaling and the self-incompatibility response. This paper shows that the kinase domain of ARK1 autophosphorylates on serine and threonine residues when expressed as a recombinant fusion protein. ARK1 produces a 2.9 kb transcript encoding a transmembrane receptor protein kinase and a 1.4 kb transcript encoding the receptor domain alone. Constitutive high-level expression of ARK1 transcripts in transgenic Arabidopsis resulted in severe stunting and also disrupted normal cellular expansion and differentiation.
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PMID:An S-locus-related gene in Arabidopsis encodes a functional kinase and produces two classes of transcripts. 881 66

In the S locus-controlled self-incompatibility system of Brassica, recognition of self-related pollen at the surface of stigma epidermal cells leads to inhibition of pollen tube development. The female (stigmatic) determinant of this recognition reaction is a polymorphic transmembrane receptor protein kinase encoded at the S locus. Another highly polymorphic, anther-expressed gene, SCR, also encoded at the S locus, fulfills the requirements for the hypothesized pollen determinant. Loss-of-function and gain-of-function studies prove that the SCR gene product is necessary and sufficient for determining pollen self-incompatibility specificity, possibly by acting as a ligand for the stigmatic receptor.
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PMID:The male determinant of self-incompatibility in Brassica. 1061 May 66