Mammalian PASKIN, a PAS-serine/threonine kinase related to bacterial oxygen sensors

The PAS domain is a versatile protein fold found in many archaeal, bacteria l, and plant proteins capable of sensing environmental changes in light int ensity, oxygen concentration, and redox potentials. The oxygen sensor FixL from Rhizobium species contains a heme-bearing PAS domain and a histidine k inase domain that couples sensing to signaling. We identified a novel mamma lian PAS protein (PASKIN) containing a domain architecture resembling FixL. PASKIN is encoded by an evolutionarily conserved single-copy gene which is ubiquitously expressed. The human PASKIN and mouse Paskin genes show a con served intronexon structure and share their promoter regions with another u biquitously expressed gene that encodes a regulator of protein phosphatase- 1. The 144-kDa PASKIN protein contains a PAS region homologous to the FixL PAS domain and a serine/threonine kinase domain which might be involved in signaling. Thus, PASKIN is likely to function as a mammalian PAS sensor pro tein. (C) 2001 Academic Press.