The protein max is a member of the basic helix-loop-helixleucine zipper (bHLHZ) family of transcription factors. It is able to form homodimers and heterodimers with other family members, which include Mad, Mxl1 and Myc. Myc is an oncoprotein implicated in cell proliferation, differentiation and apoptosis. The homodimers and heterodimers compete for a common DNA target site (the E-box) and rearrangement among these dimer forms provides a complex system of transcriptional regulation. Multiple alternatively spliced transcript variants have been described for this gene but the full-length nature for some of them is unknown.[2]
Max binds to itself and to other transcription factors through its leucine zipper to form homo- and hetero-dimers respectively. Max itself lacks a transactivation domain so that Max homodimers have a repressive function. In contrast, Myc contains a transactivation domain but cannot homodimerize. However Myc can heterodimerize with Max to form heterodimers that can both bind DNA and transactivate. The transcriptionally active Max/Myc dimer promotes cell proliferation as well as apoptosis.[3]
This gene has been shown mutated in cases of hereditary pheochromocytoma.[20] More recently the MAX gene has been shown to be mutated also in small cell lung cancer (SCLC). This is mutually exclusive with alterations at MYC and BRG1, the latter coding for an ATPase of the SWI/SNF complex. It was demonstrated that BRG1 regulates the expression of MAX through direct recruitment to the MAX promoter, and that depletion of BRG1 strongly hinders cell growth, specifically in MAX-deficient cells, heralding a synthetic lethal interaction. Furthermore, MAX required BRG1 to activate neuroendocrine transcriptional programs and to up-regulate MYC-targets, such as glycolytic-related genes.[21]
↑Amati B, Land H (February 1994). "Myc-Max-Mad: a transcription factor network controlling cell cycle progression, differentiation and death". Curr. Opin. Genet. Dev. 4 (1): 102–8. doi:10.1016/0959-437X(94)90098-1. PMID8193530.
↑Ewing RM, Chu P, Elisma F, Li H, Taylor P, Climie S, McBroom-Cerajewski L, Robinson MD, O'Connor L, Li M, Taylor R, Dharsee M, Ho Y, Heilbut A, Moore L, Zhang S, Ornatsky O, Bukhman YV, Ethier M, Sheng Y, Vasilescu J, Abu-Farha M, Lambert JP, Duewel HS, Stewart II, Kuehl B, Hogue K, Colwill K, Gladwish K, Muskat B, Kinach R, Adams SL, Moran MF, Morin GB, Topaloglou T, Figeys D (2007). "Large-scale mapping of human protein-protein interactions by mass spectrometry". Mol. Syst. Biol. 3: 89. doi:10.1038/msb4100134. PMC1847948. PMID17353931.
↑ 6.06.1McMahon SB, Van Buskirk HA, Dugan KA, Copeland TD, Cole MD (August 1998). "The novel ATM-related protein TRRAP is an essential cofactor for the c-Myc and E2F oncoproteins". Cell. 94 (3): 363–74. doi:10.1016/S0092-8674(00)81479-8. PMID9708738.
↑Cheng SW, Davies KP, Yung E, Beltran RJ, Yu J, Kalpana GV (May 1999). "c-MYC interacts with INI1/hSNF5 and requires the SWI/SNF complex for transactivation function". Nat. Genet. 22 (1): 102–5. doi:10.1038/8811. PMID10319872.
↑ 8.08.1Mac Partlin M, Homer E, Robinson H, McCormick CJ, Crouch DH, Durant ST, Matheson EC, Hall AG, Gillespie DA, Brown R (February 2003). "Interactions of the DNA mismatch repair proteins MLH1 and MSH2 with c-MYC and MAX". Oncogene. 22 (6): 819–25. doi:10.1038/sj.onc.1206252. PMID12584560.
↑ 11.011.1Billin AN, Eilers AL, Queva C, Ayer DE (December 1999). "Mlx, a novel Max-like BHLHZip protein that interacts with the Max network of transcription factors". J. Biol. Chem. 274 (51): 36344–50. doi:10.1074/jbc.274.51.36344. PMID10593926.
↑ 12.012.1Gupta K, Anand G, Yin X, Grove L, Prochownik EV (March 1998). "Mmip1: a novel leucine zipper protein that reverses the suppressive effects of Mad family members on c-myc". Oncogene. 16 (9): 1149–59. doi:10.1038/sj.onc.1201634. PMID9528857.
↑ 14.014.1Nair SK, Burley SK (January 2003). "X-ray structures of Myc-Max and Mad-Max recognizing DNA. Molecular bases of regulation by proto-oncogenic transcription factors". Cell. 112 (2): 193–205. doi:10.1016/S0092-8674(02)01284-9. PMID12553908.
↑ 15.015.115.215.3FitzGerald MJ, Arsura M, Bellas RE, Yang W, Wu M, Chin L, Mann KK, DePinho RA, Sonenshein GE (April 1999). "Differential effects of the widely expressed dMax splice variant of Max on E-box vs initiator element-mediated regulation by c-Myc". Oncogene. 18 (15): 2489–98. doi:10.1038/sj.onc.1202611. PMID10229200.
↑Meroni G, Cairo S, Merla G, Messali S, Brent R, Ballabio A, Reymond A (July 2000). "Mlx, a new Max-like bHLHZip family member: the center stage of a novel transcription factors regulatory pathway?". Oncogene. 19 (29): 3266–77. doi:10.1038/sj.onc.1203634. PMID10918583.
↑Ayer DE, Kretzner L, Eisenman RN (January 1993). "Mad: a heterodimeric partner for Max that antagonizes Myc transcriptional activity". Cell. 72 (2): 211–22. doi:10.1016/0092-8674(93)90661-9. PMID8425218.
↑Rual JF, Venkatesan K, Hao T, Hirozane-Kishikawa T, Dricot A, Li N, Berriz GF, Gibbons FD, Dreze M, Ayivi-Guedehoussou N, Klitgord N, Simon C, Boxem M, Milstein S, Rosenberg J, Goldberg DS, Zhang LV, Wong SL, Franklin G, Li S, Albala JS, Lim J, Fraughton C, Llamosas E, Cevik S, Bex C, Lamesch P, Sikorski RS, Vandenhaute J, Zoghbi HY, Smolyar A, Bosak S, Sequerra R, Doucette-Stamm L, Cusick ME, Hill DE, Roth FP, Vidal M (October 2005). "Towards a proteome-scale map of the human protein-protein interaction network". Nature. 437 (7062): 1173–8. doi:10.1038/nature04209. PMID16189514.
↑Comino-Méndez I, Gracia-Aznárez FJ, Schiavi F, Landa I, Leandro-García LJ, Letón R, Honrado E, Ramos-Medina R, Caronia D, Pita G, Gómez-Graña A, de Cubas AA, Inglada-Pérez L, Maliszewska A, Taschin E, Bobisse S, Pica G, Loli P, Hernández-Lavado R, Díaz JA, Gómez-Morales M, González-Neira A, Roncador G, Rodríguez-Antona C, Benítez J, Mannelli M, Opocher G, Robledo M, Cascón A (July 2011). "Exome sequencing identifies MAX mutations as a cause of hereditary pheochromocytoma". Nat. Genet. 43 (7): 663–7. doi:10.1038/ng.861. PMID21685915.
↑Romero OA, Torres-Diz M, Pros E, Savola S, Gomez A, Moran S, Saez C, Iwakawa R, Villanueva A, Montuenga LM, Kohno T, Yokota J, Sanchez-Cespedes M (Dec 2013). "MAX inactivation in small-cell lung cancer disrupts the MYC-SWI/SNF programs and is synthetic lethal with BRG1". Cancer Discov. 4: 292–303. doi:10.1158/2159-8290.CD-13-0799. PMID24362264.
Further reading
Grandori C, Cowley SM, James LP, Eisenman RN (2001). "The Myc/Max/Mad network and the transcriptional control of cell behavior". Annu. Rev. Cell Dev. Biol. 16: 653–99. doi:10.1146/annurev.cellbio.16.1.653. PMID11031250.
Mäkelä TP, Koskinen PJ, Västrik I, Alitalo K (1992). "Alternative forms of Max as enhancers or suppressors of Myc-ras cotransformation". Science. 256 (5055): 373–7. doi:10.1126/science.256.5055.373. PMID1566084.
Gilladoga AD, Edelhoff S, Blackwood EM, Eisenman RN, Disteche CM (1992). "Mapping of MAX to human chromosome 14 and mouse chromosome 12 by in situ hybridization". Oncogene. 7 (6): 1249–51. PMID1594250.
Blackwood EM, Eisenman RN (1991). "Max: a helix-loop-helix zipper protein that forms a sequence-specific DNA-binding complex with Myc". Science. 251 (4998): 1211–7. doi:10.1126/science.2006410. PMID2006410.
Bousset K, Henriksson M, Lüscher-Firzlaff JM, Litchfield DW, Lüscher B (1993). "Identification of casein kinase II phosphorylation sites in Max: effects on DNA-binding kinetics of Max homo- and Myc/Max heterodimers". Oncogene. 8 (12): 3211–20. PMID8247525.
Ayer DE, Kretzner L, Eisenman RN (1993). "Mad: a heterodimeric partner for Max that antagonizes Myc transcriptional activity". Cell. 72 (2): 211–22. doi:10.1016/0092-8674(93)90661-9. PMID8425218.
Västrik I, Koskinen PJ, Alitalo R, Mäkelä TP (1993). "Alternative mRNA forms and open reading frames of the max gene". Oncogene. 8 (2): 503–7. PMID8426752.
Ferré-D'Amaré AR, Prendergast GC, Ziff EB, Burley SK (1993). "Recognition by Max of its cognate DNA through a dimeric b/HLH/Z domain". Nature. 363 (6424): 38–45. doi:10.1038/363038a0. PMID8479534.
Brownlie P, Ceska T, Lamers M, Romier C, Stier G, Teo H, Suck D (1997). "The crystal structure of an intact human Max-DNA complex: new insights into mechanisms of transcriptional control". Structure. 5 (4): 509–20. doi:10.1016/S0969-2126(97)00207-4. PMID9115440.
Gupta K, Anand G, Yin X, Grove L, Prochownik EV (1998). "Mmip1: a novel leucine zipper protein that reverses the suppressive effects of Mad family members on c-myc". Oncogene. 16 (9): 1149–59. doi:10.1038/sj.onc.1201634. PMID9528857.
Lavigne P, Crump MP, Gagné SM, Hodges RS, Kay CM, Sykes BD (1998). "Insights into the mechanism of heterodimerization from the 1H-NMR solution structure of the c-Myc-Max heterodimeric leucine zipper". J. Mol. Biol. 281 (1): 165–81. doi:10.1006/jmbi.1998.1914. PMID9680483.
FitzGerald MJ, Arsura M, Bellas RE, Yang W, Wu M, Chin L, Mann KK, DePinho RA, Sonenshein GE (1999). "Differential effects of the widely expressed dMax splice variant of Max on E-box vs initiator element-mediated regulation by c-Myc". Oncogene. 18 (15): 2489–98. doi:10.1038/sj.onc.1202611. PMID10229200.