RAB23, member RAS oncogene family
The RAB23 gene provides instructions for making a protein that is involved in a process called vesicle trafficking, which moves proteins and other molecules within cells in sac-like structures called vesicles. A vesicle forms when the cell membrane folds around a substance outside the cell (such as a protein). The vesicle is drawn into the cell, pinched off from the cell membrane (a process called endocytosis), and attached to the Rab23 protein. Once inside the cell, the vesicle is guided by the Rab23 protein to its proper destination. Vesicle trafficking is important for the transport of materials that are needed to trigger signaling during development.
Through the transport of certain proteins, the Rab23 protein regulates a specific developmental pathway called the hedgehog signaling pathway that is critical in cell growth (proliferation), cell specialization, and the normal shaping (patterning) of many parts of the body during embryonic development.
More than a dozen mutations in the RAB23 gene have been found to cause Carpenter syndrome, a condition characterized by irregular skull formation, finger and toe abnormalities, and many other features. One mutation that is frequently seen in individuals with Carpenter syndrome who are of northern European ancestry replaces the protein building block (amino acid) leucine with a premature stop signal at protein position 145 (written as Leu145Term or L145X). This mutation results in an abnormally short, unstable protein that is quickly broken down. Other RAB23 gene mutations that cause Carpenter syndrome reduce or eliminate function of the Rab23 protein. It is not clear how these mutations result in the specific features of Carpenter syndrome; however, it is likely that impaired transport of proteins involved in the hedgehog signaling pathway contributes to the development of this disorder.
- RAB family small GTP binding protein RAB 23
- ras-related protein Rab-23