PAS Kinase: An Evolutionarily Conserved PAS Domain-Regulated serine/threonine Kinase

Proc Natl Acad Sci U S A. 2001 Jul 31;98(16):8991-6. doi: 10.1073/pnas.161284798. Epub 2001 Jul 17.

Abstract

PAS domains regulate the function of many intracellular signaling pathways in response to both extrinsic and intrinsic stimuli. PAS domain-regulated histidine kinases are common in prokaryotes and control a wide range of fundamental physiological processes. Similarly regulated kinases are rare in eukaryotes and are to date completely absent in mammals. PAS kinase (PASK) is an evolutionarily conserved gene product present in yeast, flies, and mammals. The amino acid sequence of PASK specifies two PAS domains followed by a canonical serine/threonine kinase domain, indicating that it might represent the first mammalian PAS-regulated protein kinase. We present evidence that the activity of PASK is regulated by two mechanisms. Autophosphorylation at two threonine residues located within the activation loop significantly increases catalytic activity. We further demonstrate that the N-terminal PAS domain is a cis regulator of PASK catalytic activity. When the PAS domain-containing region is removed, enzyme activity is significantly increased, and supplementation of the purified PAS-A domain in trans selectively inhibits PASK catalytic activity. These studies define a eukaryotic signaling pathway suitable for studies of PAS domains in a purified in vitro setting.

Publication types

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

MeSH terms

  • Amino Acid Sequence
  • Cloning, Molecular
  • Conserved Sequence*
  • Evolution, Molecular*
  • HeLa Cells
  • Humans
  • Immunohistochemistry
  • Molecular Sequence Data
  • Phosphorylation
  • Protein-Serine-Threonine Kinases / chemistry
  • Protein-Serine-Threonine Kinases / genetics
  • Protein-Serine-Threonine Kinases / metabolism*
  • Sequence Homology, Amino Acid
  • Subcellular Fractions / enzymology
  • Substrate Specificity
  • Transfection

Substances

  • PAS domain kinases
  • Protein-Serine-Threonine Kinases

Associated data

  • GENBANK/AF387103