Disease relevance of SCR

• Analysis of two S (sterility) locus haplotypes demonstrates that the A. lyrata S locus contains tightly linked orthologs of the S locus receptor kinase (SRK) gene and the S locus cysteine-rich protein (SCR) gene, which are the determinants of SI specificity in stigma and pollen, respectively, but lacks an S locus glycoprotein gene [1].

High impact information on SCR

• From analyses of gene expression and cell identity in genetically stable and unstable alleles of shr, we conclude that SHR functions upstream of SCR and participates in a radial signaling pathway [2].
• The deduced amino acid sequence of SCARECROW (SCR) suggests that it is a member of a novel family of putative transcription factors [3].
• SCR is expressed in the cortex/endodermal initial cells and in the endodermal cell lineage [3].
• Using this system, we show that SCR acts cell-autonomously to control asymmetric cell division within the ground tissue [4].
• We show that the putative transcription factor SCARECROW (SCR), first identified by its role in radial patterning, is required cell-autonomously for distal specification of the QC, which in turn regulates stem cell fate of immediately surrounding cells [5].

Biological context of SCR

• Analysis of SCR expression and the mutant phenotype from the earliest stages of embryogenesis revealed a tight correlation between defective cell divisions and SCR expression in cells that contribute to ground tissue radial patterning in both embryonic root and shoot [6].
• Endodermis-specific expression of SGR3 and ZIG by using the SCR promoter could complement the abnormal shoot gravitropism of each mutant [7].
• We therefore investigated whether morning glory SCR (PnSCR) is involved in the weeping phenotype [8].
• A number of Arabidopsis Expressed Sequence Tags (ESTs) have been identified that encode gene products bearing remarkable similarity to SCR throughout their carboxyl-termini, indicating that SCR is the prototype of a novel gene family [9].
• Here we show that the Arabidopsis genome includes two large gene families with homology to SCR and to the PCP gene family, respectively [10].

Associations of SCR with chemical compounds

• The male component of the self-incompatibility response in Brassica has recently been shown to be encoded by the S locus cysteine-rich gene (SCR) [10].
• A remarkable feature of pea SCR protein was the presence of asparagine stretches at the N-terminal transcriptional activation domain, which was distinct from the occurrence of glutamine or alanine stretches in the Arabidopsis or maize SCR [11].

Other interactions of SCR

• One of them, SCL3, has a tissue-specific pattern of expression in the root similar to SCR [9].
• RGA1, RGA2 and SCR share several structural features and may define a new family of genes [12].
• In addition, expression of SCARECROW (SCR) in the quiescent center (QC) disappeared in the disorganized RAM of tsk mutant [13].

Analytical, diagnostic and therapeutic context of SCR

• Sequence analysis of the products of the GRAS (GAI, RGA, SCR) gene family indicates that they share a variable amino-terminus and a highly conserved carboxyl-terminus that contains five recognizable motifs [9].
• A Northern blot analysis revealed a single 3.2-kb pea SCR transcript in addition to a closely related 2.5-kb transcript [11].
• Our in situ hybridization data indicated that pea SCR mRNA accumulated in the shoot apical meristem, leaf primordia and a root single cell layer corresponding to the endodermis [11].

References