BROWSE

Related Researcher

Author's Photo

Cho, Moo Je
Ulsan National Institute of Science and Technology
Research Interests
  • Calcium Signaling
  • Calmodulin
  • Plant Defense Mechanism

ITEM VIEW & DOWNLOAD

Differential activation of NAD kinase by plant calmodulin isoforms - The critical role of domain I

Cited 54 times inthomson ciCited 54 times inthomson ci
Title
Differential activation of NAD kinase by plant calmodulin isoforms - The critical role of domain I
Author
Lee, SHSeo, HYKim, JCHeo, WDChung, WSLee, KJKim, MCCheong, YHChoi, JYLim, COCho, Moo Je
Keywords
SITE-SPECIFIC MUTAGENESIS; LIGHT-CHAIN KINASE; ENZYME ACTIVATION; ESCHERICHIA-COLI; PEPTIDE COMPLEX; TARGET ENZYMES; CENTRAL HELIX; PROTEIN; BINDING; RECOGNITION
Issue Date
1997-04
Publisher
AMER SOC BIOCHEMISTRY MOLECULAR BIOLOGY INC
Citation
JOURNAL OF BIOLOGICAL CHEMISTRY, v.272, no.14, pp.9252 - 9259
Abstract
NAD kinase is a Ca2+/calmodulin (CaM)-dependent enzyme capable of converting cellular NAD to NADP. The enzyme purified from pea seedlings can be activated by highly conserved soybean CaM, SCaM-1, but not by the divergent soybean CaM isoform, SCaM-4 (Lee, S. H., Kim, J. C., Lee, M. S., Heo, W. D., Seo, H. Y., Yoon, H. W., Hong, J. C., Lee, S. Y., Bahk, J. D., Hwang, I., and Cho, M. J. (1995) J. Biol. Chem. 270, 21806-21812). To determine which domains were responsible for this differential activation of NAD kinase, a series of chimeric SCaMs were generated by exchanging functional domains between SCaM-4 and SCaM-1. SCaM-4111, a chimeric SCaM-1 that contains the first domain of SCaM-4, was severely impaired (only 40% of maximal) in its ability to activate NAD kinase. SCaM-1444, a chimeric SCaM-4 that contains the first domain of SCaM-1 exhibited nearly full (~70%) activation of NAD kinase. Only chimeras containing domain I of SCaM-1 produced greater than half-maximal activation of NAD kinase. To define the amino acid residue(s) in domain I that were responsible for this differential activation, seven single residue substitution mutants of SCaM-1 were generated and tested for NAD kinase activation. Among these mutants, only K30E and G40D showed greatly reduced NAD kinase activation. Also a double residue substitution mutant, K30E/G40D, containing these two mutations in combination was severely impaired in its NAD kinase-activating potential, reaching only 20% of maximal activation. Furthermore, a triple mutation, K30E/M36I/G40D, completely abolished NAD kinase activation. Thus, our data suggest that domain I of CaM plays a key role in the differential activation of NAD kinase exhibited by SCaM-1 and SCaM-4. Further, the residues Lys30 and Glu40 of SCaM-1 are critical for this function.
URI
Go to Link
ISSN
0021-9258
Appears in Collections:
BME_Journal Papers
Files in This Item:
2-s2.0-0001281471.pdf Download

find_unist can give you direct access to the published full text of this article. (UNISTARs only)

Show full item record

qrcode

  • mendeley

    citeulike

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.

MENU