Molecular Cloning, Functional Expression and mRNA Analysis of Human Beta-Adrenergic Receptor Kinase 2

In the present study the cDNA of human βARK2 was cloned using both PCR and cDNA library screening, subcloned into an expression vector and transiently expressed in COS7 cells. The expressed kinase activity was ∼40% as efficient as human βARK1 in phosphorylating bovine rod outer segments in vitro. Northern blot analysis of human and bovine mRNA revealed a species-specific pattern of multiple hybridization bands, with two major transcripts in human rather than one in bovine. High levels of mRNA expression were found in peripheral blood leukocytes.