CBL

Domain

The RING-type zinc finger domain mediates binding to an E2 ubiquitin-conjugating enzyme.

The N-terminus is composed of the phosphotyrosine binding (PTB) domain, a short linker region and the RING-type zinc finger. The PTB domain, which is also called TKB (tyrosine kinase binding) domain, is composed of three different subdomains: a four-helix bundle (4H), a calcium-binding EF hand and a divergent SH2 domain.

Function

Adapter protein that functions as a negative regulator of many signaling pathways that are triggered by activation of cell surface receptors. Acts as an E3 ubiquitin-protein ligase, which accepts ubiquitin from specific E2 ubiquitin-conjugating enzymes, and then transfers it to substrates promoting their degradation by the proteasome (PubMed:17094949). Ubiquitinates SPRY2 (PubMed:17094949, PubMed:17974561). Ubiquitinates EGFR (PubMed:17974561). Recognizes activated receptor tyrosine kinases, including KIT, FLT1, FGFR1, FGFR2, PDGFRA, PDGFRB, CSF1R, EPHA8 and KDR and terminates signaling. Recognizes membrane-bound HCK, SRC and other kinases of the SRC family and mediates their ubiquitination and degradation. Participates in signal transduction in hematopoietic cells. Plays an important role in the regulation of osteoblast differentiation and apoptosis. Essential for osteoclastic bone resorption. The 'Tyr-731' phosphorylated form induces the activation and recruitment of phosphatidylinositol 3-kinase to the cell membrane in a signaling pathway that is critical for osteoclast function. May be functionally coupled with the E2 ubiquitin-protein ligase UB2D3. In association with CBLB, required for proper feedback inhibition of ciliary platelet-derived growth factor receptor-alpha (PDGFRA) signaling pathway via ubiquitination and internalization of PDGFRA (By similarity).

Involvement in disease

Noonan syndrome-like disorder with or without juvenile myelomonocytic leukemia

NSLL

A syndrome characterized by a phenotype reminiscent of Noonan syndrome. Clinical features are highly variable, including facial dysmorphism, short neck, developmental delay, hyperextensible joints and thorax abnormalities with widely spaced nipples. The facial features consist of triangular face with hypertelorism, large low-set ears, ptosis, and flat nasal bridge. Some patients manifest cardiac defects. Some have an increased risk for certain malignancies, particularly juvenile myelomonocytic leukemia.

None

The disease is caused by variants affecting the gene represented in this entry.

Pathway

Protein modification; protein ubiquitination.

Post-translational modifications

Phosphorylated on tyrosine residues by ALK, EGFR, SYK, FYN and ZAP70 (By similarity). Phosphorylated on tyrosine residues in response to FLT1 and KIT signaling. Phosphorylated on tyrosine residues by INSR and FGR. Phosphorylated on several tyrosine residues by constitutively activated FGFR3. Not phosphorylated at Tyr-731 by FGFR3. Phosphorylated on tyrosine residues by activated CSF1R, PDGFRA and PDGFRB. Phosphorylated on tyrosine residues by HCK.

Ubiquitinated, leading to its degradation via the proteasome (PubMed:11896602, PubMed:20094046). Ubiquitination is negatively regulated by IFT20 (PubMed:29237719).

Cellular localization

• Cytoplasm
• Cell membrane
• Cell projection
• Cilium
• Golgi apparatus
• Colocalizes with FGFR2 in lipid rafts at the cell membrane.

Alternative names

• E3 ubiquitin-protein ligase CBL
• Casitas B-lineage lymphoma proto-oncogene
• Proto-oncogene c-Cbl
• RING finger protein 55
• RING-type E3 ubiquitin transferase CBL
• Signal transduction protein CBL
• RNF55
• CBL2
• CBL

Database links

• entrezGene:867
• omim:165360
• swissprot:P22681

Target type

Proteins

Primary research area

Epigenetics

Molecular weight

99633Da