Caenorhabditis elegans OSR-1 regulates behavioral and physiological responses to hyperosmotic environments

Genetics. 2004 May;167(1):161-70. doi: 10.1534/genetics.167.1.161.

Abstract

The molecular mechanisms that enable multicellular organisms to sense and modulate their responses to hyperosmotic environments are poorly understood. Here, we employ Caenorhabditis elegans to characterize the response of a multicellular organism to osmotic stress and establish a genetic screen to isolate mutants that are osmotic stress resistant (OSR). In this study, we describe the cloning of a novel gene, osr-1, and demonstrate that it regulates osmosensation, adaptation, and survival in hyperosmotic environments. Whereas wild-type animals exposed to hyperosmotic conditions rapidly lose body volume, motility, and viability, osr-1(rm1) mutant animals maintain normal body volume, motility, and viability even upon chronic exposures to high osmolarity environments. In addition, osr-1(rm1) animals are specifically resistant to osmotic stress and are distinct from previously characterized osmotic avoidance defective (OSM) and general stress resistance age-1(hx546) mutants. OSR-1 is expressed in the hypodermis and intestine, and expression of OSR-1 in hypodermal cells rescues the osr-1(rm1) phenotypes. Genetic epistasis analysis indicates that OSR-1 regulates survival under osmotic stress via CaMKII and a conserved p38 MAP kinase signaling cascade and regulates osmotic avoidance and resistance to acute dehydration likely by distinct mechanisms. We suggest that OSR-1 plays a central role in integrating stress detection and adaptation responses by invoking multiple signaling pathways to promote survival under hyperosmotic environments.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Caenorhabditis elegans
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / physiology*
  • Cloning, Molecular
  • Down-Regulation
  • Epistasis, Genetic
  • Models, Genetic
  • Molecular Sequence Data
  • Mutation
  • Osmosis*
  • Phenotype
  • Physical Chromosome Mapping
  • RNA Interference
  • Signal Transduction
  • Stress, Physiological
  • Time Factors
  • p38 Mitogen-Activated Protein Kinases / metabolism

Substances

  • Caenorhabditis elegans Proteins
  • OSR-1 protein, C elegans
  • p38 Mitogen-Activated Protein Kinases

Associated data

  • GENBANK/AY360470