Casitas B Lineage Lymphoma Like Protein 1 (CBLL1)

Mutation analysis showed that after phosphorylation, CDH1-specific tyrosine residues mediate the interaction with Hakai, which does not bind to CDH2, CDH11, or the cytoplasmic domains of other tyrosine kinase receptors. By searching sequence databases, the authors identified a human homolog of Hakai. The deduced 491-amino acid human protein, which is 97% identical to the mouse protein, contains a C3HC4-type RING finger at its N terminus, typical of E3 ubiquitin ligases, a phospho-tyrosine binding area, and a proline-rich C terminus. Molecular modeling suggested that HAKAI contains a minimal SH2 domain preceded by a combined RING and zinc finger domain. Northern blot analysis of mouse tissues revealed wide expression of 4.8- and 2.5-kb transcripts.