DYRK1B is a member of the DYRK family of protein kinases. DYRK1B contains a bipartite nuclear localization signal and is found mainly in muscle and testis. The protein is proposed to be involved in the regulation of nuclear functions. Three isoforms of DYRK1B have been identified differing in the presence of two alternatively spliced exons within the catalytic domain. [provided by RefSeq].