In 1989 a virally encoded portion of the chromosomal mouse Cbl gene was the first member of the Cbl family to be discovered[6] and was named v-Cbl to distinguish it from normal mouse c-Cbl. The virus used in the experiment was a mouse-tropic strain of Murine leukemia virus isolated from the brain of a mouse captured at Lake Casitas, California known as Cas-Br-M,[7] and was found to have excised approximately a third of the original c-Cbl gene from a mouse into which it was injected. Sequencing revealed that the portion carried by the retrovirus encoded a tyrosine kinase binding domain, and that this was the oncogenic form as retroviruses carrying full-length c-Cbl did not induce tumor formation. The resultant transformed retrovirus was found to consistently induce a type of pre-B lymphoma, known as Casitas B-lineage lymphoma, in infected mice.
Proline-rich region: the site of interaction between Cbl and cytosolic proteins involved in Cbl's adaptor functions
C-terminalubiquitin-associated domain (UBA domain): the site of ubiquitin binding
This domain structure and the tyrosine and serine-rich content of the protein product is typical of an "adaptor molecule" used in cell signalling pathways.[8]
Three mammalian homologues have been characterized, which all differ in their ability to function as adaptor proteins due to the differing lengths of their C-terminal UBA domains:
c-Cbl: ubiquitously expressed, 906 and 913 amino acids in length in humans and mice respectively
Cbl-c: lacks the UBA domain and is therefore only 474 amino acids in length. It is primarily expressed in epithelial cells however its function is poorly understood.
Ubiquitination is the process of chemically attaching ubiquitin monomers to a protein, thereby targeting it for degradation. As this is a multi-step process, several different enzymes are involved, the final one being a member of the E3 family of ligases. Cbl functions as an E3 ligase, and therefore is able to catalyse the formation of a covalent bond between ubiquitin and Cbl's protein substrate - typically a receptor tyrosine kinase. The RING-finger domain mediates this transfer, however like other E3 ligases of the RING type no intermediate covalent bond is formed between ubiquitin and the RING-finger domain. The stepwise attachment of ubiquitin to the substrate receptor tyrosine kinase can lead to its removal from the plasma membrane and subsequent trafficking to the lysosome for degradation.
^ abPetrelli A, Gilestro GF, Lanzardo S, Comoglio PM, Migone N, Giordano S (March 2002). "The endophilin-CIN85-Cbl complex mediates ligand-dependent downregulation of c-Met". Nature. 416 (6877): 187–90. Bibcode:2002Natur.416..187P. doi:10.1038/416187a. PMID11894096. S2CID4389099.
^ abcdHaglund K, Ivankovic-Dikic I, Shimokawa N, Kruh GD, Dikic I (May 2004). "Recruitment of Pyk2 and Cbl to lipid rafts mediates signals important for actin reorganization in growing neurites". J. Cell Sci. 117 (Pt 12): 2557–68. doi:10.1242/jcs.01148. PMID15128873. S2CID14083271.
^Cormont M, Metón I, Mari M, Monzo P, Keslair F, Gaskin C, McGraw TE, Le Marchand-Brustel Y (February 2003). "CD2AP/CMS regulates endosome morphology and traffic to the degradative pathway through its interaction with Rab4 and c-Cbl". Traffic. 4 (2): 97–112. doi:10.1034/j.1600-0854.2003.40205.x. PMID12559036. S2CID38612642.
^ abHusson H, Mograbi B, Schmid-Antomarchi H, Fischer S, Rossi B (May 1997). "CSF-1 stimulation induces the formation of a multiprotein complex including CSF-1 receptor, c-Cbl, PI 3-kinase, Crk-II and Grb2". Oncogene. 14 (19): 2331–8. doi:10.1038/sj.onc.1201074. PMID9178909. S2CID967748.
^ abcdErdreich-Epstein A, Liu M, Kant AM, Izadi KD, Nolta JA, Durden DL (April 1999). "Cbl functions downstream of Src kinases in Fc gamma RI signaling in primary human macrophages". J. Leukoc. Biol. 65 (4): 523–34. doi:10.1002/jlb.65.4.523. PMID10204582. S2CID18340540.
^Chin H, Saito T, Arai A, Yamamoto K, Kamiyama R, Miyasaka N, Miura O (October 1997). "Erythropoietin and IL-3 induce tyrosine phosphorylation of CrkL and its association with Shc, SHP-2, and Cbl in hematopoietic cells". Biochem. Biophys. Res. Commun. 239 (2): 412–7. doi:10.1006/bbrc.1997.7480. PMID9344843.
^ abTvorogov D, Carpenter G (July 2002). "EGF-dependent association of phospholipase C-gamma1 with c-Cbl". Exp. Cell Res. 277 (1): 86–94. doi:10.1006/excr.2002.5545. PMID12061819.
^Liu SK, McGlade CJ (December 1998). "Gads is a novel SH2 and SH3 domain-containing adaptor protein that binds to tyrosine-phosphorylated Shc". Oncogene. 17 (24): 3073–82. doi:10.1038/sj.onc.1202337. PMID9872323. S2CID6140122.
^Howlett CJ, Bisson SA, Resek ME, Tigley AW, Robbins SM (April 1999). "The proto-oncogene p120(Cbl) is a downstream substrate of the Hck protein-tyrosine kinase". Biochem. Biophys. Res. Commun. 257 (1): 129–38. doi:10.1006/bbrc.1999.0427. PMID10092522.
^Sehat B, Andersson S, Girnita L, Larsson O (July 2008). "Identification of c-Cbl as a new ligase for insulin-like growth factor-I receptor with distinct roles from Mdm2 in receptor ubiquitination and endocytosis". Cancer Res. 68 (14): 5669–77. doi:10.1158/0008-5472.CAN-07-6364. PMID18632619.
^Park RK, Izadi KD, Deo YM, Durden DL (September 1999). "Role of Src in the modulation of multiple adaptor proteins in FcalphaRI oxidant signaling". Blood. 94 (6): 2112–20. doi:10.1182/blood.V94.6.2112. PMID10477741.
^Zhang S, Broxmeyer HE (January 1999). "p85 subunit of PI3 kinase does not bind to human Flt3 receptor, but associates with SHP2, SHIP, and a tyrosine-phosphorylated 100-kDa protein in Flt3 ligand-stimulated hematopoietic cells". Biochem. Biophys. Res. Commun. 254 (2): 440–5. doi:10.1006/bbrc.1998.9959. PMID9918857.
^Dufour C, Guenou H, Kaabeche K, Bouvard D, Sanjay A, Marie PJ (June 2008). "FGFR2-Cbl interaction in lipid rafts triggers attenuation of PI3K/Akt signaling and osteoblast survival". Bone. 42 (6): 1032–9. doi:10.1016/j.bone.2008.02.009. PMID18374639.
^Wakioka T, Sasaki A, Mitsui K, Yokouchi M, Inoue A, Komiya S, Yoshimura A (May 1999). "APS, an adaptor protein containing Pleckstrin homology (PH) and Src homology-2 (SH2) domains inhibits the JAK-STAT pathway in collaboration with c-Cbl". Leukemia. 13 (5): 760–7. doi:10.1038/sj/leu/2401397. PMID10374881.
^Borinstein SC, Hyatt MA, Sykes VW, Straub RE, Lipkowitz S, Boulter J, Bogler O (December 2000). "SETA is a multifunctional adapter protein with three SH3 domains that binds Grb2, Cbl, and the novel SB1 proteins". Cell. Signal. 12 (11–12): 769–79. doi:10.1016/S0898-6568(00)00129-7. PMID11152963.
^Vandenbroere I, Paternotte N, Dumont JE, Erneux C, Pirson I (January 2003). "The c-Cbl-associated protein and c-Cbl are two new partners of the SH2-containing inositol polyphosphate 5-phosphatase SHIP2". Biochem. Biophys. Res. Commun. 300 (2): 494–500. doi:10.1016/S0006-291X(02)02894-2. PMID12504111.
Lupher ML, Andoniou CE, Bonita D, Miyake S, Band H (1998). "The c-Cbl oncoprotein". Int. J. Biochem. Cell Biol. 30 (4): 439–44. doi:10.1016/S1357-2725(97)00075-7. PMID9675877.
Fang N, Fang D, Wang HY, Altman A, Liu YC (2002). "Regulation of immune responses by E3 ubiquitin-protein ligases". Curr. Dir. Autoimmun. Current Directions in Autoimmunity. 5: 161–75. doi:10.1159/000060552. ISBN3-8055-7308-1. PMID11826757.