BRAF (gene)

BRAF

Symbol	BRAF
HGNC ID	1097
Alternative symbols	–
Entrez Gene	673
OMIM	164757
RefSeq	NM_004333
UniProt	P15056
Chromosome	7q34
Locus supplementary data	–

BRAF is a gene that encodes a protein called B-Raf, which is a member of the Raf kinase family of growth signal transduction protein kinases. B-Raf is involved in sending signals inside cells, which are involved in directing cell growth. Mutations in this gene have been associated with various forms of cancer, including melanoma, colorectal cancer, and thyroid cancer.

Function

B-Raf is a serine/threonine protein kinase that plays a role in the MAPK/ERK pathway, which is a chain of proteins in the cell that communicates a signal from a receptor on the surface of the cell to the DNA in the nucleus. The MAPK/ERK pathway is involved in the regulation of meiosis, mitosis, and postmitotic functions in differentiated cells. B-Raf is activated by binding to Ras, which is a small GTPase, and subsequently phosphorylates and activates MEK1 and MEK2, which in turn activate ERK1 and ERK2.

Clinical significance

Mutations in the BRAF gene are implicated in a variety of cancers. The most common mutation, V600E, results in a valine to glutamic acid substitution at position 600, which leads to constitutive activation of the B-Raf protein. This mutation is found in approximately 50% of melanomas and is also present in other cancers such as colorectal cancer and papillary thyroid carcinoma.

File:BRAF Kinase Inactive.png

Inactive form of BRAF kinase

Targeted therapies have been developed to inhibit the activity of mutant B-Raf proteins. One such drug is vemurafenib, which specifically targets the V600E mutation. Another drug, sorafenib, is a multi-kinase inhibitor that targets B-Raf among other kinases.

File:Sorafenib BRAF Labeled.png

Sorafenib binding to BRAF

Research and developments

Research continues to explore the role of BRAF mutations in cancer and the development of new therapeutic strategies. Combination therapies that target multiple pathways are being investigated to overcome resistance to BRAF inhibitors.

Also see

• MAPK/ERK pathway
• Ras (protein)
• Vemurafenib
• Sorafenib
• Melanoma
• Colorectal cancer
• Thyroid cancer