Arabidopsis SHEPHERD, an HSP90-like molecular chaperone resident in the ER, buffers harmful genetic variations in CLAVATA2

Abstract

Among Arabidopsis genes, CLAVATA2 (CLV2) harbors exceptionally many strain-specific polymorphisms accompanying amino-acid substitutions. However, it has not been elucidated the mechanism how such highly polymorphic genes are allowed to be exist. We have shown that CLV2^Ws, a CLV2 in Ws strain, requires for its function the SHEPHERD (SHD), which is an HSP90-like molecular chaperone resident in the endoplasmic reticulum. Our aim is to verify the hypothesis that the chaperone activity of SHD dissolves harmful misfolding of mutated CLV2, allows such mutated genes to behave as functional alleles, and functions as a capacitor of genetic variation.
Recently, we determined a single amino-acid substitution in CLV2^Ws as the caused mutation for SHD requirement. Then we identified 32 types of CLV2 amino-acid sequences among 93 Arabidopsis strains. SHD dependency of these CLV2 variants will be reported.