Abstract
Amino acid substitutions in proteins usually cause decreased functional activity. However, Rutherford and Lindquist (1998) proposed that the Hsp90 has ability to restore the function of mutated proteins and allowed them to survive against selection pressure. According to this theory, it was expected that there exists many proteins with cryptic mutations whose functions are dependent on Hsp90.
We had already reported that (1) Because of amino acid substitution, CLAVATA2 in Arabidopsis Ws accession (CLV2Ws) requires the chaperone activity of SHEPHERD (SHD), which is an Hsp90-like molecular chaperone resident in the endoplasmic reticulum, for its functional maturation, while CLV2Col does not. (2) SHD directly interacts with CLV2 in vitro. From these results, we thought the relationship between SHD and CLV2 was an example of the above theory.
Furthermore, Arabidopsis exceptionally harbors many amino acid substitutions in CLV2, and we expected some of them were also dependent on SHD. Therefore, we analyzed the SHD dependency of various CLV2, and results of this analysis will be reported.
