Members of the KIN2/PAR-1/MARK kinase subfamily are conserved from yeast to human and share the same domain organisation: an N-terminal kinase domain and a C-terminal kinase associated domain 1 (KA1). Some members of the KIN1/PAR-1/MARK family also contain an UBA domain (see <PDOC50030>). Members of this kinase subfamily are involved in various biological processes such as cell polarity, cell cycle control, intracellular signaling, microtubule stability and protein stability [1]. The function of the KA1 domain is not yet known.

Some proteins known to contain a KA1 domain are listed below:

• Mammalian MAP/microtubule affinity-regulating kinases (MARK 1,2,3). They regulate polarity in neuronal cell models and appear to function redundantly in phosphorylating MT-associated proteins and in regulating MT stability [2].
• Mammalian maternal embryonic leucine zipper kinase (MELK). It phosphorylates ZNF622 and may contribute to its redirection to the nucleus. It may be involved in the inhibition of spliceosome assembly during mitosis.
• Caenorhabditis elegans and drosophila PAR-1 protein. It is required for establishing polarity in embryos where it is assimetrically distributed [3].
• Fungal Kin1 and Kin2 protein kinases involved in regulation of exocytosis. They localize to the cytoplasmic face of the plasma membrane [4].
• Plant KIN10 and KIN11 proteins, catalytic subunits of the putative trimeric SNF1-related protein kinase (SnRK) complex.

The profile we developed covers the entire KA1 domain.