Dataset Information

Salt enhances calmodulin-target interaction.

ABSTRACT: Calmodulin (CaM) operates as a Ca(2+) sensor and is known to interact with and regulate hundreds of proteins involved in a great many aspects of cellular function. It is of considerable interest to understand the balance of forces in complex formation of CaM with its target proteins. Here we have studied the importance of electrostatic interactions in the complex between CaM and a peptide derived from smooth-muscle myosin light-chain kinase by experimental methods and Monte Carlo simulations of electrostatic interactions. We show by Monte Carlo simulations that, in agreement with experimental data, the binding affinity between CaM and highly charged peptides is surprisingly insensitive to changes in the net charge of both the protein and peptide. We observe an increase in the binding affinity between oppositely charged partners with increasing salt concentration from zero to 100 mM, showing that formation of globular CaM-kinase type complexes is facilitated at physiological ionic strength. We conclude that ionic interactions in complex formation are optimized at pH and saline similar to the cell environment, which probably overrules the electrostatic repulsion between the negatively charged Ca(2+)-binding domains of CaM. We propose a conceivable rationalization of CaM electrostatics associated with interdomain repulsion.

SUBMITTER: Andre I

PROVIDER: S-EPMC1414561 | biostudies-literature | 2006 Apr

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Salt enhances calmodulin-target interaction.

André Ingemar I Kesvatera Tõnu T Jönsson Bo B Linse Sara S

Biophysical journal 20060120 8

Calmodulin (CaM) operates as a Ca(2+) sensor and is known to interact with and regulate hundreds of proteins involved in a great many aspects of cellular function. It is of considerable interest to understand the balance of forces in complex formation of CaM with its target proteins. Here we have studied the importance of electrostatic interactions in the complex between CaM and a peptide derived from smooth-muscle myosin light-chain kinase by experimental methods and Monte Carlo simulations of ...[more]

PMID: 16428276

Similar Datasets

Project description:BackgroundCalmodulin (CaM) is an important calcium sensor protein that transduces Ca2+ signals in plant stress signaling pathways. A previous study has revealed that transgenic rice over-expressing the calmodulin gene OsCam1-1 (LOC_Os03g20370) is more tolerant to salt stress than wild type. To elucidate the role of OsCam1-1 in the salt stress response mechanism, downstream components of the OsCam1-1-mediated response were identified and investigated by transcriptome profiling and target identification.ResultsTranscriptome profiling of transgenic 'Khao Dawk Mali 105' rice over-expressing OsCam1-1 and wild type rice showed that overexpression of OsCam1-1 widely affected the expression of genes involved in several cellular processes under salt stress, including signaling, hormone-mediated regulation, transcription, lipid metabolism, carbohydrate metabolism, secondary metabolism, photosynthesis, glycolysis, tricarboxylic acid (TCA) cycle and glyoxylate cycle. Under salt stress, the photosynthesis rate in the transgenic rice was slightly lower than in wild type, while sucrose and starch contents were higher, suggesting that energy and carbon metabolism were affected by OsCam1-1 overexpression. Additionally, four known and six novel CaM-interacting proteins were identified by cDNA expression library screening with the recombinant OsCaM1. GO terms enriched in their associated proteins that matched those of the differentially expressed genes affected by OsCam1-1 overexpression revealed various downstream cellular processes that could potentially be regulated by OsCaM1 through their actions.ConclusionsThe diverse cellular processes affected by OsCam1-1 overexpression and possessed by the identified CaM1-interacting proteins corroborate the notion that CaM signal transduction pathways compose a complex network of downstream components involved in several cellular processes. These findings suggest that under salt stress, CaM activity elevates metabolic enzymes involved in central energy pathways, which promote or at least maintain the production of energy under the limitation of photosynthesis.

Dataset Information

Salt enhances calmodulin-target interaction.

Publications

Salt enhances calmodulin-target interaction.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets