PAS Domain Containing Serine/Threonine Protein Kinase (PASK)

PAS domains regulate the function of many intracellular signaling pathways in response to both extrinsic and intrinsic stimuli. PASK is an evolutionarily conserved protein present in yeast, flies, and mammals.The 1,323-amino acid PASK protein contains 2 PAS domains, designated PAS-A and PAS-B, followed by a canonical serine/threonine kinase domain and a 75-amino acid hydrophilic tail. Human PASK purified from insect cells infected with a recombinant baculovirus encoding the full-length protein migrated on SDS-PAGE with an apparent molecular mass of 145 kD, similar to its predicted molecular mass. Transient transfection of human embryonic kidney cells with fluorescence-tagged PASK resulted in immunofluorescence that tended to predominate in the perinuclear region.