MYB (gene)

Myb proto-oncogene protein also known as transcriptional activator Myb is a is_associated_with::protein that in humans is encoded by the MYB is_associated_with::gene.

Function
Myb proto-oncogene protein is a member of the MYB (myeloblastosis) family of is_associated_with::transcription factors. The protein contains three domains, an N-terminal is_associated_with::DNA-binding domain, a central transcriptional activation domain and a C-terminal domain involved in transcriptional repression. This protein plays an essential role in the regulation of is_associated_with::hematopoiesis and may play a role in is_associated_with::tumorigenesis, including the regulation of miR-155 in B-cells.

Plant orthologs
MYB factors represent a family of proteins that include the conserved MYB DNA-binding domain. Plants contain a MYB-protein subfamily that is characterised by the R2R3-type MYB domain.

In maize, is_associated_with::phlobaphenes are synthesized in the flavonoids synthetic pathway from polymerisation of is_associated_with::flavan-4-ols which encodes an R2R3 myb-like is_associated_with::transcriptional activator of the A1 gene encoding for the is_associated_with::dihydroflavonol 4-reductase (reducing is_associated_with::dihydroflavonols into flavan-4-ols) while another gene (Suppressor of Pericarp Pigmentation 1 or SPP1) acts as a suppressor. The maize P gene encodes a Myb homolog that recognizes the sequence CCT/AACC, in sharp contrast with the C/TAACGG bound by vertebrate Myb proteins.

In sorghum, the corresponding yellow seed 1 gene (y1) also encodes a R2R3 type of Myb domain protein that regulates the expression of is_associated_with::chalcone synthase, is_associated_with::chalcone isomerase and is_associated_with::dihydroflavonol reductase genes required for the biosynthesis of is_associated_with::3-deoxyflavonoids.

Ruby is a MYB transcriptional activator of genes that produce anthocyanin in citrus fruits. In most citrus varieties Ruby is non-functional, but in blood oranges it upregulates anthocyanin production to produce the characteristic red color of the fruit.