Transcription factor MafB also known as V-maf musculoaponeurotic fibrosarcoma oncogene homolog B is a protein

Protein

Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...

 that in humans is encoded by the MAFB gene

Gene

A gene is a molecular unit of heredity of a living organism. It is a name given to some stretches of DNA and RNA that code for a type of protein or for an RNA chain that has a function in the organism. Living beings depend on genes, as they specify all proteins and functional RNA chains...

. This gene maps to chromosome

Chromosome

A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...

 20q11.2-q13.1, consists of a single exon and spans around 3 kb.

Function

MafB is a basic leucine zipper (bZIP

BZIP domain

The Basic Leucine Zipper Domain is found in many DNA binding eukaryotic proteins. One part of the domain contains a region that mediates sequence specific DNA binding properties and the leucine zipper that is required for the dimerization of two DNA binding regions. The DNA binding region...

) transcription factor

Transcription factor

In molecular biology and genetics, a transcription factor is a protein that binds to specific DNA sequences, thereby controlling the flow of genetic information from DNA to mRNA...

 that plays an important role in the regulation of lineage-specific hematopoiesis. The encoded nuclear protein represses ETS1

ETS1

Protein C-ets-1 is a protein that in humans is encoded by the ETS1 gene. The protein encoded by this gene belongs to the ETS family of transcription factors.-Interactions:ETS1 has been shown to interact with TTRAP, UBE2I and Death associated protein 6....

-mediated transcription of erythroid-specific genes in myeloid

Myeloid

The term myeloid suggests an origin in the bone marrow or spinal cord, or a resemblance to the marrow or spinal cord.In hematopoiesis, the term "myeloid cell" is used to describe any leukocyte that is not a lymphocyte...

 cells.

Clinical significance

Mutations in the murine Mafb gene are responsible for the mutant mouse Kreisler (kr) that presents an abnormal segmentation of the hindbrain and exhibit hyperactive behavior, including head tossing and running in circles. This mice dies at birth due to renal failure whereas the Mafb -/- mice dies of central apnea.

Recently, single-nucleotide polymorphisms (SNPs) near MAFB have been found associated with nonsyndromic cleft lip and palate in a genomewide association study involving 1,908 case-parent trios from Europe, the United States, China, Taiwan, Singapore, Korea, and the Philippines. Mafb mRNA and protein were detected in both craniofacial ectoderm and neural crest-derived mesoderm between embryonic days 13.5 and 14.5; expression was strong in the epithelium around the palatal shelves and in the medial edge epithelium during palatal fusion. After fusion, Mafb expression was stronger in oral epithelium compared to mesenchymal tissue. In addition, sequencing analysis detected a new missense mutation

Missense mutation

In genetics, a missense mutation is a point mutation in which a single nucleotide is changed, resulting in a codon that codes for a different amino acid . This can render the resulting protein nonfunctional...

in the Filipino population, H131Q, that was significantly more frequent in cases than in matched controls.

External links