Spans 55,6 kb; 18 exons

3,6kb mRNA of MARK4S isoform, 3,22kb of MARK4L isoform (alternative splicing-skipping of exon 16, which leads to a change in the reading frame ).

688 amino acids (aa) for MARK4S isoform and 752 aa for MARK4L isoform; belongs to the MARK family of protein kinases and contains from aa 59 to 314 a Serine-Threonine kinase catalytic domain with two activating phosphorylation sites. A short sequence (T region) contains a putative membrane-targeting motif. This region is followed by a ubiquitin-associated (UBA) domain. The spacer is the least-conserved region among MARKs proteins. This region is followed by a strikingly conserved C-terminal domain. In MARK4 the C-terminal domain differs between MARK4S and MARK4L isoforms.

The MARK4S isoform is predominantly expressed in the brain and at low levels in the heart. The MARK4L isoform is expressed ubiquitously in all tissues, with a highly abundant expression in testis, neural progenitors and glial tumors. MARK4L is downregulated during glial differentiation.

Protein was detected homogeneously in cytoplasm.

MARK4 is considered to play a role as a messenger of the Wnt-signaling pathway. MARK4L represents a mitogenic-associated isoform.

MARK1, MARK2 (Emk1), MARK3 (p78/C-TAK1), par1, kin1

Mutations have not been detected.