UBA domain found in casitas B-lineage lymphoma (Cbl) proteins
The Cbl adaptor proteins family contains a small class of RING-type E3 ubiquitin ligases with oncogenic activity which is represented by three mammalian members, c-Cbl, Cbl-b and Cbl-3. Cbl proteins function as potent negative regulators of various signaling cascades in a wide range of cell types. They play roles in ubiquitinating the activated tyrosine kinases and targeting them for degradation. Cbl proteins in this family consists of a highly conserved N-terminal half that includes a tyrosine-kinase-binding (TKB) domain and a RING finger domain, both of which are required for Cbl-mediated downregulation of RTKs, and a C-terminal half that includes a ubiquitin-associated (UBA) domain and other protein interaction motifs. The UBA domain contains leucine/isoleucine repeats and may play a role in dimerization of Cbl proteins. In addition, although both c-Cbl and Cbl-b have the C-terminal UBA domain, only the UBA domain from Cbl-b can bind ubiquitin.
Jiyao W et al.(2023). "The conserved domain database in 2023.",