The gene encompasses 229 kb, and has 9 exons.

Nine different isoforms have been described for MITF, each with different 5 specificity (MITF -A, -J, -C, -MC, -E, -H, -D, -B, -M). All isoforms have exons 2-9 in common, encoding the functional domains of the transcription factors. Exon 1 is variable and the domains within it are the transactivation domain (TAD) and the beta-helix-loop-helix-zipper (B-HLH-Zip). Some isoforms are specific for certain cells types, i.e. M: melanocytes, MC: mast cells (Levy et al., 2006).

526 aa, 58795 Da.
Regulates the differentiation and development of melanocytes, neural crest-derived cells, retinal epithelium (optic cup-derived retinal pigment epithelium), mast cells, and osteoclasts (Lin and Fisher, 2007; Adijanto et al., 2012).

Post translational modifications:
- Phosphorylation at Ser-405 significantly enhances the ability to bind the tyrosinase promoter.
- Phosphorylation at Ser-180 and Ser-516 by MAPK and RPS6KA1 activate the transcription factor activity and promote ubiquitiniation and subsequent degradation.
- Can be deubiquitinated by USP13, preventing its degradation.

Found in most human tissues. Particularly high quantities in retina, uterus, pineal gland, and adipocytes (biogps.org).

Nucleus.

A transcription factor that activates the transcription of tyrosinase and tyrosinase-related protein 1 (TYRP1), and dopachrome tautomerase (DCT). These are enzymes that are specifically expressed in melanocytes (Yasumoto et al., 1995). For tyrosinase, MITF binds to a symmetrical DNA sequence found in the promoter region: a restricted subset of E-box motives containing canonical CATGTG sequence flanked by a 5 thymidine (Aksan and Goding, 1998). The regulation of the DCT promoter is even more complex and involves other proteins like CREB and SOX10; and PAX3 has an inhibitory effect on DCT activation by MITF (Bertolotto et al., 1998; Ludwig et al., 2004; Lang et al., 2005).
Not only does MITF activate genes involved in melanin synthesis, it also activates the transcription of genes involved in melanosome structure (PMEL17, MART-1), biogenesis (ocular albinism type 1 gene), and transport (RAB27A) (Du et al., 2003; Vetrini et al., 2004; Chiaverini et al., 2008). Also, MITF activates the transcription of the melanocortin 1 receptor gene which encodes a melanocyte-stimulating hormone receptor normally present on the plasma membrane of melanocytes: this binding is the first step in the hormonal regulation of pigmentation (Vachtenheim and Borovansky, 2010).
In addition, MITF plays a role in apoptosis through several target genes, showing importance of MITF in melanocyte development and survival. MITF controls the transcription of BCL-2, and known inhibitor of apoptosis (McGill et al., 2002). Therefore, MITF mutation may explain the reduced number of melanocytes in certain disorders (Samija et al., 2010). MITF also induces transcription of melanoma-inhibitor-of-apoptosis (BIRC7, ML-IAP) (Dynek et al., 2008). Furthermore, it regulates a receptor for hepatocyte growth factor (MET), whose activation inhibits melanocyte apoptosis (Beuret et al., 2007).
MITF also plays a role in melanocyte proliferation by regulating several genes involved in the cell-cycle: cyclin-dependant kinase 2 (CDK2), transcription factor TBX2, and Dia1 protein (Diaph1). These promote cell-cycle progression, prevent senescence and cell-cycle arrest, and increase cellular proliferation, respectively (Du et al., 2004; Carreira et al., 2005; Carreira et al., 2006). However, MITF also has anti-proliferative properties by way of inducing cell-cycle arrest by activating cyclin-dependent kinase inhibitor 1A and 2A (CDKN1A/p21, CDKN2A/p16) (Carreira et al., 2005; Loercher et al., 2005). It has believed that both depletion and over-expression inhibit proliferation whereas normal levels promote proliferation (Kido et al., 2009).
MITF also has important roles in osteoclast and mast cell development and function. In osteoclasts it activates transcription of functional proteins tartrate-resistant alkaline phosphatase (TRAP), cathepsin K, OSCAR, e-cadherin, OSTM1 and CLCN7 (Meadows et al., 2007). In mast cells MITF activates the transcription of mast cell proteases 2,4,5,6, and 9, granzyme B, tryptophan hydroxylase, and kit, all important for differentiation and function (Kitamura et al., 2006).
Up-stream regulation: LysRS-Ap4A-MITF signaling pathway (Lee et al., 2004); Wnt signaling pathway (Takeda et al., 2000); alpha melanocyte-stimulating hormone signaling pathway (Bertolotto et al., 1998).

High homology to TFE genes (TFE3, TFEB, TFEC, etc.) and the myc family of bHLH transcription factors (Dickson et al., 2011).

The MITF promoter is partially regulated by certain transcription factors such as PAX3, SOX10, LEF-1/TCF and CREB during development. Mutations affecting the MITF and the MITF pathway lead to pigmentary and auditory defects (Cimadamore et al., 2012; Pierrat et al., 2012).

Mutations in the MITF at germline will lead to syndromes with pigmentary and/or auditory defects. Mutations in MITF are also known to give a predisposition to certain cancers, including melanoma and renal cell carcinoma (Bertolotto et al., 2011). Heterozygous mutations lead to auditory/pigmentary syndromes such as Waardenburg type 2 and Tietz syndrome (Lin and Fisher, 2007).