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Updated: Jun 9, 2026

Forward Genetic Screen Using Transgenic Calcium Reporter Aequorin to Identify Novel Targets in Calcium Signaling
Published on: August 1, 2020
AtCML8, a calmodulin-like protein, differentially activating CaM-dependent enzymes in Arabidopsis thaliana
Hyeong Cheol Park1, Chan Young Park, Sung Cheol Koo
1Division of Applied Life Science (BK21 Program), Plant Molecular Biology and Biotechnology Research Center, Jinju, Korea. hcpark@gnu.ac.kr
Abstract:
Plants express many calmodulins (CaMs) and calmodulin-like (CML) proteins that sense and transduce different Ca(2+) signals. Previously, we reported divergent soybean (Glycine max) CaM isoforms (GmCaM4/5) with differential abilities to activate CaM-dependent enzymes. To elucidate biological functions of divergent CaM proteins, we isolated a cDNA encoding a CML protein, AtCML8, from Arabidopsis. AtCML8 shows highest identity with GmCaM4 at the protein sequence level. Expression of AtCML8 was high in roots, leaves, and flowers but low in stems. In addition, the expression of AtCML8 was induced by exposure to salicylic acid or NaCl. AtCML8 showed typical characteristics of CaM such as Ca(2+)-dependent electrophoretic mobility shift and Ca(2+) binding ability. In immunoblot analyses, AtCML8 was recognized only by antiserum against GmCaM4 but not by GmCaM1 antibodies. Interestingly, AtCML8 was able to activate phosphodiesterase (PDE) but did not activate NAD kinase. These results suggest that AtCML8 acts as a CML protein in Arabidopsis with characteristics similar to soybean divergent GmCaM4 at the biochemical levels.
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