The receptor tyrosine kinase HIR-1 coordinates HIF-independent responses to hypoxia and extracellular matrix injury

Sci Signal. 2018 Oct 2;11(550):eaat0138. doi: 10.1126/scisignal.aat0138.


Inadequate tissue oxygen, or hypoxia, is a central concept in the pathophysiology of ischemic disorders and cancer. Hypoxia promotes extracellular matrix (ECM) remodeling, cellular metabolic adaptation, and cancer cell metastasis. To discover new pathways through which cells respond to hypoxia, we performed a large-scale forward genetic screen in Caenorhabditis elegans and identified a previously uncharacterized receptor tyrosine kinase named HIR-1. Loss of function in hir-1 phenocopied the impaired ECM integrity associated with hypoxia or deficiency in the oxygen-dependent dual oxidase, heme peroxidases, or cuticular collagens involved in ECM homeostasis. Genetic suppressor screens identified NHR-49 and MDT-15 as transcriptional regulators downstream of HIR-1. Furthermore, hir-1 mutants showed defects in adapting to and recovering from prolonged severe hypoxia. We propose that C. elegans HIR-1 coordinates hypoxia-inducible factor-independent responses to hypoxia and hypoxia-associated ECM remodeling through mechanisms that are likely conserved in other organisms.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caenorhabditis elegans Proteins / genetics*
  • Caenorhabditis elegans Proteins / metabolism
  • Extracellular Matrix / metabolism*
  • Gene Expression Profiling / methods*
  • Gene Expression Regulation*
  • Homeostasis / genetics
  • Hypoxia*
  • Receptor Protein-Tyrosine Kinases / genetics*
  • Receptor Protein-Tyrosine Kinases / metabolism
  • Receptors, Cytoplasmic and Nuclear / genetics
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Signal Transduction / genetics
  • Transcription Factors / genetics
  • Transcription Factors / metabolism


  • Caenorhabditis elegans Proteins
  • MDT-15 protein, C elegans
  • NHR-49 protein, C elegans
  • Receptors, Cytoplasmic and Nuclear
  • Transcription Factors
  • Receptor Protein-Tyrosine Kinases