CDC-LIKE KINASE 4; CLK4

HGNC Approved Gene Symbol: CLK4

Cytogenetic location: 5q35.3 Genomic coordinates (GRCh38): 5:178,602,663-178,627,049 (from NCBI)

▼ Cloning and Expression
By searching an EST database for CDC-like kinases, followed by RT-PCR of total kidney RNA, Schultz et al. (2001) cloned CLK4. The deduced 481-amino acid protein has a calculated molecular mass of about 54 kD. CLK4 shares 97% identity with murine Clk4. Northern blot analysis detected 4 transcripts that ranged from about 2.0 to 4.5 kb. Strongest expression was in liver, kidney, heart, skeletal muscle, and brain. All 4 transcripts were expressed evenly in kidney and liver, while the 2.8-kb transcript predominated in heart and skeletal muscle. Analysis of a multiple tissue expression array showed CLK4 expression in all samples tested.

▼ Gene Function
Schultz et al. (2001) demonstrated that recombinant CLK4 expressed in E. coli phosphorylated myelin basic protein (159430) and autophosphorylated, but it did not phosphorylate H2B (see 609904). CLK4 containing a lys189-to-arg mutation was catalytically inactive.

▼ Mapping
By FISH, Schultz et al. (2001) mapped the CLK4 gene to chromosome 5q35.