CBLL1

The E3 ubiquitin-protein ligase Hakai (HAKAI) also known as Casitas B-lineage lymphoma-transforming sequence-like protein 1 (CBLL1) is an enzyme that in humans is encoded by the CBLL1 gene. This gene encodes an E3 ubiquitin ligase for the E-cadherin complex and mediates its ubiquitination, endocytosis, and degradation in the lysosomes. The encoded protein contains a RING-finger domain and is also thought to have a role in control of cell proliferation.

Function

Hakai functions as a RING finger domain-containing E3 ubiquitin ligase for E-cadherin. Hakai mediates E-cadherin ubiquitination and its degradation by proteasomes. "Hakai" means "destruction" in Japanese. Proteosomal degradation of E-cadherin can be regulated by phosphorylation. The Hakai binding site is a part of the E-cadherin cytoplasmic domain that contains several tyrosines. Tyrosine kinases such as Src and Met can phosphorylate E-cadherin and enhance Hakai binding to E-cadherin. Two lysines of the E-cadherin cytoplasmic domain have been shown to be sites for ubiquitination. Hakai also interacts with polypyrimidine tract-binding protein-associated splicing factor.

See also

• CBL (gene); the gene name "CBLL1" comes from "Cbl-like protein 1"

External links

• Human CBLL1 genome location and CBLL1 gene details page in the UCSC Genome Browser.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.