MLANA

Melan-A

Rendering of a MHC protein complexed with a MLANA derived peptide (yellow), from PDB 2GUO
Available structures
PDB Ortholog search: PDBe, RCSB
Identifiers
Symbols MLANA ; MART-1; MART1
External IDs OMIM: 605513 MGI: 108454 HomoloGene: 4026 GeneCards: MLANA Gene
RNA expression pattern
More reference expression data
Orthologs
Species Human Mouse
Entrez 2315 77836
Ensembl ENSG00000120215 ENSMUSG00000024806
UniProt Q16655 Q2TA50
RefSeq (mRNA) NM_005511 NM_029993
RefSeq (protein) NP_005502 NP_084269
Location (UCSC) Chr 9:
5.89 – 5.91 Mb
Chr 19:
29.7 – 29.71 Mb
PubMed search

Protein melan-A also known as melanoma antigen recognized by T cells 1 or MART-1 is a protein that in humans is encoded by the MLANA gene.[1] A fragment of the protein, usually consisting of the nine amino acids 27 to 35, is bound by MHC class I complexes which present it to T cells of the immune system. These complexes can be found on the surface of melanoma cells. Decameric peptides (26-35) are being investigated as cancer vaccines.

Discovery and nomenclature

The names MART-1 and melan-A were coined by two groups of researchers who independently sequenced the gene for this antigen in 1994. Both names are currently in common use. Kawakami et al. at the National Cancer Institute coined the term MART-1, which stands for "melanoma antigen recognized by T-cells."[2] Coulie et al. of Belgium called the gene melan-A, presumably an abbreviation for "melanocyte antigen."[3]

Clinical significance

MART-1/melan-A is a protein antigen that is found on the surface of melanocytes. Antibodies against the antigen are used in the medical specialty of anatomic pathology in order to recognize cells of melanocytic differentiation, useful for the diagnosis of a melanoma. The same name is also used to refer to the gene which codes for the antigen.

The MART-1/melan-A antigen is specific for the melanocyte lineage, found in normal skin, the retina, and melanocytes, but not in other normal tissues. It is thus useful as a marker for melanocytic tumors (melanomas) with the caveat that it is normally found in benign nevi as well.

In many immunological studies melan-A peptides serve as a positive control for T-cell priming experiments. This is due to the fact that its precursor frequency among cytotoxic T-cells is one of the highest known so far, making it easy for antigen presenting cells to evoke peptide-specific responses.

Structure

MART-1/melan-A is a putative 18 kDa transmembrane protein consisting of 118 amino acids. It has a single transmembrane domain.

Regulation

Its expression is regulated by the Microphthalmia-associated transcription factor.[4][5]

References

  1. "Entrez Gene: MLANA melan-A".
  2. Kawakami Y, Eliyahu S, Delgado CH, Robbins PF, Rivoltini L, Topalian SL, Miki T, Rosenberg SA (April 1994). "Cloning of the gene coding for a shared human melanoma antigen recognized by autologous T cells infiltrating into tumor". Proc. Natl. Acad. Sci. U.S.A. 91 (9): 3515–9. doi:10.1073/pnas.91.9.3515. PMC 43610. PMID 8170938.
  3. Coulie PG, Brichard V, Van Pel A, Wölfel T, Schneider J, Traversari C, Mattei S, De Plaen E, Lurquin C, Szikora JP, Renauld JC, Boon T (July 1994). "A new gene coding for a differentiation antigen recognized by autologous cytolytic T lymphocytes on HLA-A2 melanomas". J. Exp. Med. 180 (1): 35–42. doi:10.1084/jem.180.1.35. PMC 2191574. PMID 8006593.
  4. Du J, Miller AJ, Widlund HR, Horstmann MA, Ramaswamy S, Fisher DE (2003). "MLANA/MART1 and SILV/PMEL17/GP100 are transcriptionally regulated by MITF in melanocytes and melanoma". Am. J. Pathol. 163 (1): 333–43. doi:10.1016/S0002-9440(10)63657-7. PMC 1868174. PMID 12819038.
  5. Hoek KS, Schlegel NC, Eichhoff OM, et al. (2008). "Novel MITF targets identified using a two-step DNA microarray strategy". Pigment Cell Melanoma Res. 21 (6): 665–76. doi:10.1111/j.1755-148X.2008.00505.x. PMID 19067971.

Further reading


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