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.
Moon
Byeong Cheol
BC
Division of Applied Life Science (BK21 program), Plant Molecular Biology and Biotechnology Research Center, Gyeongsang National University, Jinju 660-701, Korea.
Choi
Man Soo
MS
Kang
Yun Hwan
YH
Kim
Min Chul
MC
Cheong
Mi Sun
MS
Park
Chan Young
CY
Yoo
Jae Hyuk
JH
Koo
Sung Cheol
SC
Lee
Sang Min
SM
Lim
Chae Oh
CO
Cho
Moo Je
MJ
Chung
Woo Sik
WS
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