Identification of centaurin-alpha2: a phosphatidylinositide-binding protein present in fat, heart and skeletal muscle

Eur J Cell Biol. 2002 Apr;81(4):222-30. doi: 10.1078/0171-9335-00242.


We describe here the cloning, expression and characterisation of centaurin-alpha2 from a rat adipocyte cDNA library. The centaurin-alpha2 cDNA contains an open reading frame, which codes for a protein of 376 amino acids with predicted mass of 43.5 kDa. Centaurin-alpha2 shares 51-59% identity with centaurin-alpha1 proteins and has the same domain organisation, consisting of a predicted N-terminal ArfGAP domain followed by two successive pleckstrin homology domains. Despite the sequence similarity, there are a number of notable differences between the previously characterised centaurin-alpha1 proteins and the newly described centaurin-alpha2: (i) in vitro lipid binding experiments with centaurin-alpha2 do not reveal the same selectivity for phosphatidylinositol 3,4,5-trisphosphate over phosphatidylinositol 4,5-bisphosphate that has been shown for centaurin-alpha; (ii) unlike centaurin-alpha1 which is expressed mainly in the brain, centaurin-alpha2 has a broad tissue distribution, being particularly abundant in fat, heart and skeletal muscle; (iii) in contrast to centaurin-alpha1 which is found in both membrane and cytosolic fractions, endogenous centaurin-alpha2 is exclusively present in the dense membrane fractions of cell extracts, suggesting a constitutive membrane association. Insulin stimulation, which stimulates phosphatidylinositol 3,4,5-trisphosphate production, does not alter the subcellular distribution of centaurin-alpha2 between adipocyte membrane fractions. This observation is consistent with the lack of specificity of centaurin-alpha2 for phosphatidylinositol 3,4,5-trisphosphate over phosphatidylinositol 4,5-bisphosphate.

Publication types

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

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Adipose Tissue / chemistry*
  • Adipose Tissue / metabolism
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Carrier Proteins / classification
  • Carrier Proteins / genetics*
  • Carrier Proteins / metabolism*
  • Cell Fractionation
  • Cloning, Molecular
  • GTPase-Activating Proteins
  • Humans
  • Ligands
  • Liposomes / metabolism
  • Molecular Sequence Data
  • Muscle, Skeletal / chemistry*
  • Muscle, Skeletal / metabolism
  • Myocardium / chemistry*
  • Myocardium / metabolism
  • Nerve Tissue Proteins / classification
  • Nerve Tissue Proteins / genetics*
  • Nerve Tissue Proteins / metabolism*
  • Open Reading Frames
  • Phosphatidylinositols / metabolism*
  • Phylogeny
  • Protein Binding
  • Protein Isoforms / genetics
  • Protein Isoforms / metabolism
  • Rats
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Sequence Alignment
  • Substrate Specificity
  • Tissue Distribution


  • ADAP1 protein, human
  • ADAP2 protein, human
  • Adap1 protein, rat
  • Adap2 protein, rat
  • Adaptor Proteins, Signal Transducing
  • Carrier Proteins
  • GTPase-Activating Proteins
  • Ligands
  • Liposomes
  • Nerve Tissue Proteins
  • Phosphatidylinositols
  • Protein Isoforms
  • Recombinant Proteins

Associated data

  • GENBANK/AJ238993
  • GENBANK/AJ238994