CBLB (gene)

CBL-B is an E3 ubiquitin-protein ligase that in humans is encoded by the CBLB gene. CBLB is a member of the CBL gene family.

Function
CBL-B functions as a negative regulator of T-cell activation. CBL-B expression in T cells causes ligand-induced T cell receptor down-modulation, controlling the activation degree of T cells during antigen presentation.

Clinical significance
Mutation of the CBLB gene has been associated with autoimmune conditions such as type 1 diabetes.

Interactions
CBLB has been shown to interact with:
 * CRKL,
 * Epidermal growth factor receptor,
 * Grb2,
 * NEDD4,
 * PIK3R1, and
 * SH3KBP1.