Identification of tudor repeat associator with PCTAIRE 2 (Trap). A novel protein that interacts with the N-terminal domain of PCTAIRE 2 in rat brain.
PCTAIRE 2 is a Cdc2-related kinase that is predominantly expressed in the terminally differentiated neuron. To elucidate the function of PCTAIRE 2, proteins that associate with PCTAIRE 2 were screened by the yeast two-hybrid system. A positive clone was found to encode a novel protein that could bind to PCTAIRE 2 in vitro as well as in vivo, and was designated as Trap (tudor repeat associator with PCTAIRE 2). The overall structure of Trap shows no significant homology to any proteins, but contains five repeated domains (the tudor-like domain), conserved in Drosophila tudor protein. Trap associates with the N-terminal domain of PCTAIRE 2 through its C-terminal domain, which contains two tudor-like domains. PCTAIRE 1, but not PCTAIRE 3, can also associate with Trap. Trap is predominantly expressed in brain and testis, and gradually increases during brain development throughout life, consistent with the expression pattern of PCTAIRE 2. Immunoreactivities for PCTAIRE 2 and Trap were colocalized to the mitochondria in COS 7 cells. Immunohistochemical analyses showed that PCTAIRE 2 and Trap were distributed in the same cell layer of the cerebral cortex and cerebellum. These findings suggest that Trap is a physiological partner of PCTAIRE 2 in terminally differentiated neurons.
Hirose
T
T
Division of Protein Metabolism, Institute for Protein Research, Osaka University, Japan. hirose@protein.osaka-u.ac.jp
Kawabuchi
M
M
Tamaru
T
T
Okumura
N
N
Nagai
K
K
Okada
M
M
D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000201:enzymology*; D019556:COS Cells; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D018844:Cyclin-Dependent Kinases; D018076:DNA, Complementary; D007150:Immunohistochemistry; D008969:Molecular Sequence Data; D017346:Protein Serine-Threonine Kinases / Q000737:chemistry / Q000378:metabolism*; D051381:Rats; D017386:Sequence Homology, Amino Acid; D013347:Subcellular Fractions / Q000201:enzymology / Q000378:metabolism; D020798:Two-Hybrid System Techniques
D002352:Carrier Proteins; D018076:DNA, Complementary; C407356:Tdrd7 protein, rat; D017346:Protein Serine-Threonine Kinases; D018844:Cyclin-Dependent Kinases; C109207:PCTAIRE-2 protein kinase