Arabidopsis ubiquitin-specific protease 6 (AtUBP6) interacts with calmodulin.
Calmodulin (CaM), a key Ca(2+) sensor in eukaryotes, regulates diverse cellular processes by interacting with many proteins. To identify Ca(2+)/CaM-mediated signaling components, we screened an Arabidopsis expression library with horseradish peroxidase-conjugated Arabidopsis calmodulin2 (AtCaM2) and isolated a homolog of the UBP6 deubiquitinating enzyme family (AtUBP6) containing a Ca(2+)-dependent CaM-binding domain (CaMBD). The CaM-binding activity of the AtUBP6 CaMBD was confirmed by CaM mobility shift assay, phosphodiesterase competition assay and site-directed mutagenesis. Furthermore, expression of AtUBP6 restored canavanine resistance to the Deltaubp6 yeast mutant. This is the first demonstration that Ca(2+) signaling via CaM is involved in ubiquitin-mediated protein degradation and/or stabilization in plants.
Division of Applied Life Science (BK21 program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Korea.
Byeong Cheol
BC
Moon
Man Soo
MS
Choi
Yun Hwan
YH
Kang
Min Chul
MC
Kim
Mi Sun
MS
Cheong
Chan Young
CY
Park
Jae Hyuk
JH
Yoo
Sung Cheol
SC
Koo
Sang Min
SM
Lee
Chae Oh
CO
Lim
Moo Je
MJ
Cho
Woo Sik
WS
Chung
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000201:enzymology*; D029681:Arabidopsis Proteins / Q000502:physiology*; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism; D002147:Calmodulin / Q000378:metabolism*; D002172:Canavanine / Q000737:chemistry / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D010450:Endopeptidases / Q000378:metabolism / Q000502:physiology*; D015723:Gene Library; D005816:Genetic Complementation Test; D005982:Glutathione Transferase / Q000378:metabolism; D006735:Horseradish Peroxidase / Q000378:metabolism; D006801:Humans; D008957:Models, Genetic; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009154:Mutation; D010455:Peptides / Q000737:chemistry; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D025801:Ubiquitin / Q000737:chemistry / Q000378:metabolism; D064570:Ubiquitin-Specific Proteases
D029681:Arabidopsis Proteins; C488659:CALM2 protein, human; D002147:Calmodulin; D010455:Peptides; D025801:Ubiquitin; D002172:Canavanine; D006735:Horseradish Peroxidase; D005982:Glutathione Transferase; D010727:Phosphoric Diester Hydrolases; D010450:Endopeptidases; D064570:Ubiquitin-Specific Proteases; D002118:Calcium