TBCD

Description

The TBCD (tubulin folding cofactor D) is a protein-coding gene located on chromosome 17.

Tubulin-specific chaperone D is a protein that in humans is encoded by the TBCD gene.

== Function == Cofactor D is one of four proteins (cofactors A, D, E, and C) involved in the pathway leading to correctly folded beta-tubulin from folding intermediates. Cofactors A and D are believed to play a role in capturing and stabilizing beta-tubulin intermediates in a quasi-native confirmation. Cofactor E binds to the cofactor D/beta-tubulin complex; interaction with cofactor C then causes the release of beta-tubulin polypeptides that are committed to the native state.

== Interactions == TBCD has been shown to interact with ARL2.

TBCD plays a crucial role in the initial step of tubulin folding, ensuring proper assembly of tubulin complexes. It regulates microtubule dynamics by capturing GTP-bound beta-tubulin (TUBB), influencing microtubule polymerization or depolymerization. Its interaction with beta-tubulin is controlled by its association with ARL2. TBCD functions as a GTPase-activating protein (GAP) for ARL2. In the absence of ARL2, TBCD disrupts microtubules. When overexpressed in polarized cells, TBCD increases beta-tubulin degradation. It promotes epithelial cell detachment, a process counteracted by ARL2. TBCD induces disassembly of tight adherens and tight junctions at the lateral cell membrane. TBCD is essential for accurate assembly and maintenance of the mitotic spindle, and proper progression through mitosis. It is involved in neuron morphogenesis.

TBCD is also known as PEBAT, SSD-1, tfcD.

Associated Diseases

• Encephalopathy, progressive, early-onset, with brain atrophy and thin corpus callosum
• Early-onset progressive diffuse brain atrophy-microcephaly-muscle weakness-optic atrophy syndrome