The RAF genes encode serine/threonine-protein kinases that act as links between the membrane-associated RAS GTPases and the MAPK/ERK cascade. The RAS-RAF-MEK-ERK pathway impacts proliferation, differentiation, apoptosis, and oncogenic transformation; as might be expected, many of the genes in the pathway are implicated in the development of cancer. This report describes a fly model that uses a disease-implicated variant of the human BRAF gene. There are two additional RAF genes in human, ARAF and RAF1. In Drosophila, there is a single orthologous gene, Dmel\Raf, for which classical amorphic and hypomorphic mutations, RNAi-targeting constructs, and alleles caused by insertional mutagenesis have been generated.
Several UAS constructs of the human Hsap\BRAF carrying a specific disease-implicated variant have been introduced into flies. Variant(s) implicated in human disease tested (as transgenic human gene, BRAF): the V600E variant form has been introduced into flies. The V600E variant constitutively activates the kinase and has been found in many forms of cancer (see MIM:164757).
This disease model has been designed to facilitate assessment of pharmaceutical treatment options. The GAL4-UAS system is used to express the BRAF V600E variant form in a variety of tissues; useful and easily quantitated phenotypes include lethality, semi-lethality and a rough eye phenotype. Single drugs as well as a combined treatment have been assessed.
An analogous change introduced into the Dmel\Raf gene has also been studied. Variant(s) implicated in human disease (analogous mutation in fly gene): A572E in the fly Raf gene (corresponds to V600E in the human BRAF gene).
See also the human disease model report 'cancer, multiple, RAF1-related' (FBhh0000558). Hsap\BRAF has also been used in a fly model of Noonan syndrome 7 (FBhh0001344).
[updated May 2021 by FlyBase; FBrf0222196]
Variation in the kinase domain of BRAF have been associated with various cancers. The most common BRAF variant, V600E, constitutively activates the kinase, and causes cell proliferation in the absence of growth factors that would normally be required. The V600E variant is detected in approximately 50% of melanomas. [Medgen, Vemurafenib response; 893721]
Many to one: 3 human to 1 Drosophila. The three human genes are BRAF, RAF1, and ARAF.
High-scoring ortholog of human BRAF, ARAF, RAF1 (1 Drosophila to 3 human). Dmel\Raf shares 43-47% identity and 56-60% similarity with the human genes.