The prenylation status of a novel plant calmodulin directs plasma membrane or nuclear localization of the protein.
Post-translational attachment of isoprenyl groups to conserved cysteine residues at the C-terminus of a number of regulatory proteins is important for their function and subcellular localization. We have identified a novel calmodulin, CaM53, with an extended C-terminal basic domain and a CTIL CaaX-box motif which are required for efficient prenylation of the protein in vitro and in vivo. Ectopic expression of wild-type CaM53 or a non-prenylated mutant protein in plants causes distinct morphological changes. Prenylated CaM53 associates with the plasma membrane, but the non-prenylated mutant protein localizes to the nucleus, indicating a dual role for the C-terminal domain. The subcellular localization of CaM53 can be altered by a block in isoprenoid biosynthesis or sugar depletion, suggesting that CaM53 activates different targets in response to metabolic changes. Thus, prenylation of CaM53 appears to be a novel mechanism by which plant cells can coordinate Ca2+ signaling with changes in metabolic activities.
Rodríguez-Concepción
M
M
Department of Plant and Microbial Biology, University of California, Berkeley, CA 94720, USA.
Yalovsky
S
S
Zik
M
M
Fromm
H
H
Gruissem
W
W
D000595:Amino Acid Sequence; D001483:Base Sequence; D001693:Biological Transport, Active / Q000187:drug effects; D002147:Calmodulin / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050260:Carbohydrate Metabolism; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D017931:DNA Primers / Q000235:genetics; D003624:Darkness; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors / Q000494:pharmacology; D008148:Lovastatin / Q000494:pharmacology; D019684:Magnoliopsida / Q000235:genetics / Q000378:metabolism; D008969:Molecular Sequence Data; D009154:Mutation; D010641:Phenotype; D010940:Plant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D017368:Protein Prenylation; D015398:Signal Transduction
D002147:Calmodulin; D017931:DNA Primers; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D010940:Plant Proteins; D008148:Lovastatin