Regulation of the dual specificity protein phosphatase, DsPTP1, through interactions with calmodulin
Cited 18 times inCited 18 times in
- Regulation of the dual specificity protein phosphatase, DsPTP1, through interactions with calmodulin
- Yoo, JH; Cheong, MS; Park, Chan Young; Moon, BC; Kim, MC; Kang, YH; Park, HC; Choi, MS; Lee, JH; Jung, WY; Yoon, HW; Chung, WS; Lim, CO; Lee, SY; Cho, Moo Je
- Issue Date
- AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
- JOURNAL OF BIOLOGICAL CHEMISTRY, v.279, no.2, pp.848 - 858
- Reversible phosphorylation is a key mechanism for the control of intercellular events in eukaryotic cells. In animal cells, Ca 2+/CaM-dependent protein phosphorylation and dephosphorylation are implicated in the regulation of a number of cellular processes. However, little is known on the functions of Ca2+/CaM-dependent protein kinases and phosphatases in Ca2+ signaling in plants. From an Arabidopsis expression library, we isolated cDNA encoding a dual specificity protein phosphatase 1, which is capable of hydrolyzing both phosphoserine/threonine and phosphotyrosine residues of the substrates. Using a gel overlay assay, we identified two Ca2+-dependent CaM binding domains (CaMBDI in the N terminus and CaMBDII in the C terminus). Specific binding of CaM to two CaMBD was confirmed by site-directed mutagenesis, a gel mobility shift assay, and a competition assay using a Ca2+/CaM-dependent enzyme. At increasing concentrations of CaM, the biochemical activity of dual specificity protein phosphatase 1 on the p-nitrophenyl phosphate (pNPP) substrate was increased, whereas activity on the phosphotyrosine of myelin basic protein (MBP) was inhibited. Our results collectively indicate that calmodulin differentially regulates the activity of protein phosphatase, dependent on the substrate. Based on these findings, we propose that the Ca2+ signaling pathway is mediated by CaM cross-talks with a protein phosphorylation signal pathway in plants via protein dephosphorylation.
- Appears in Collections:
- BIO_Journal Papers
- Files in This Item:
- There are no files associated with this item.
can give you direct access to the published full text of this article. (UNISTARs only)
Show full item record
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.