Myb proto-oncogene protein is a member of the MYB (myeloblastosis) family of transcription factors. The protein contains three domains, an N-terminalDNA-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 hematopoiesis and may play a role in tumorigenesis, including the regulation of miR-155 in B-cells.[3]
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.[4]
In maize, phlobaphenes are synthesized in the flavonoids synthetic pathway[5] from polymerisation of flavan-4-ols[6][7] which encodes an R2R3 myb-like transcriptional activator[8] of the A1 gene encoding for the dihydroflavonol 4-reductase (reducing dihydroflavonols into flavan-4-ols)[9] while another gene (Suppressor of Pericarp Pigmentation 1 or SPP1) acts as a suppressor.[10] 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.[11]
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.[14]
References
↑Chen Y, Xu H, Liu J, Zhang C, Leutz A, Mo X (Jul 2007). "The c-Myb functions as a downstream target of PDGF-mediated survival signal in vascular smooth muscle cells". Biochem Biophys Res Commun. 360 (2): 433–6. doi:10.1016/j.bbrc.2007.06.078. PMID17599807.
↑Vargova K, Curik N, Burda P, Basova P, Kulvait V, Pospisil V, Savvulidi F, Kokavec J, Necas E, Berkova A, Obrtlikova P, Karban J, Mraz M, Pospisilova S, Mayer J, Trneny M, Zavadil J, Stopka T (April 2011). "MYB transcriptionally regulates the miR-155 host gene in chronic lymphocytic leukemia". Blood. 117 (14): 3816–25. doi:10.1182/blood-2010-05-285064. PMID21296997.
↑Stracke R, Werber M, Weisshaar B (October 2001). "The R2R3-MYB gene family in Arabidopsis thaliana". Curr. Opin. Plant Biol. 4 (5): 447–56. doi:10.1016/s1369-5266(00)00199-0. PMID11597504.
↑Himi E, Mares DJ, Yanagisawa A, Noda K (July 2002). "Effect of grain colour gene (R) on grain dormancy and sensitivity of the embryo to abscisic acid (ABA) in wheat". J. Exp. Bot. 53 (374): 1569–74. doi:10.1093/jxb/erf005. PMID12096095.
↑Lee EA, Harper V (2002). "Suppressor of Pericarp Pigmentation 1 (SPP1), a novel gene involved in phlobaphene accumulation in maize (Zea mays L.) pericarps". Maydica. 47 (1): 51–58. INIST:13772300
↑The myb-homologous P gene controls phlobaphene pigmentation in maize floral organs by directly activating a flavonoid biosynthetic gene subset. Erich Grotewold, Bruce J. Drummond, Ben Bowen and Thomas Peterson, Cell, 11 February 199, Volume 76, Issue 3, pages 543-554, doi:10.1016/0092-8674(94)90117-1PMID8313474
↑Boddu J, Svabek C, Ibraheem F, Jones AD, Chopra S (2005). "Characterization of a deletion allele of a sorghum Myb gene yellow seedl showing loss of 3-deoxyflavonoids". Plant Science. 169 (3): 542–552. doi:10.1016/j.plantsci.2005.05.007. INIST:16983977
↑Boddu J, Jiang C, Sangar V, Olson T, Peterson T, Chopra S (January 2006). "Comparative structural and functional characterization of sorghum and maize duplications containing orthologous myb transcription regulators of 3-deoxyflavonoid biosynthesis". Plant Mol. Biol. 60 (2): 185–99. doi:10.1007/s11103-005-3568-1. PMID16429259.
Oh IH, Reddy EP (1999). "The myb gene family in cell growth, differentiation and apoptosis". Oncogene. 18 (19): 3017–33. doi:10.1038/sj.onc.1202839. PMID10378697.
Kalkbrenner F, Guehmann S, Moelling K (1990). "Transcriptional activation by human c-myb and v-myb genes". Oncogene. 5 (5): 657–61. PMID2189102.
Westin EH, Gorse KM, Clarke MF (1990). "Alternative splicing of the human c-myb gene". Oncogene. 5 (8): 1117–24. PMID2202948.
Dasgupta P, Reddy EP (1990). "Identification of alternatively spliced transcripts for human c-myb: molecular cloning and sequence analysis of human c-myb exon 9A sequences". Oncogene. 4 (12): 1419–23. PMID2687764.
Janssen JW, Vernole P, de Boer PA, Oosterhuis JW, Collard JG (1986). "Sublocalization of c-myb to 6q21----q23 by in situ hybridization and c-myb expression in a human teratocarcinoma with 6q rearrangements". Cytogenet. Cell Genet. 41 (3): 129–35. doi:10.1159/000132217. PMID3007038.
Slamon DJ, Boone TC, Murdock DC, Keith DE, Press MF, Larson RA, Souza LM (1986). "Studies of the human c-myb gene and its product in human acute leukemias". Science. 233 (4761): 347–51. doi:10.1126/science.3014652. PMID3014652.
Krieg J, Oelgeschläger M, Janknecht R, Lüscher B (1995). "High affinity DNA binding of native full length c-Myb and differential proteolytic sensitivity of its N- and C-terminal domains". Oncogene. 10 (11): 2221–8. PMID7784067.
Jacobs SM, Gorse KM, Westin EH (1994). "Identification of a second promoter in the human c-myb proto-oncogene". Oncogene. 9 (1): 227–35. PMID8302584.
Favier D, Gonda TJ (1994). "Detection of proteins that bind to the leucine zipper motif of c-Myb". Oncogene. 9 (1): 305–11. PMID8302594.
Glaser R, Lafuse WP, Bonneau RH, Atkinson C, Kiecolt-Glaser JK (1993). "Stress-associated modulation of proto-oncogene expression in human peripheral blood leukocytes". Behav. Neurosci. 107 (3): 525–9. doi:10.1037/0735-7044.107.3.525. PMID8329139.
Dash AB, Orrico FC, Ness SA (1996). "The EVES motif mediates both intermolecular and intramolecular regulation of c-Myb". Genes Dev. 10 (15): 1858–69. doi:10.1101/gad.10.15.1858. PMID8756344.
Vorbrueggen G, Lovrić J, Moelling K (1997). "Functional analysis of phosphorylation at serine 532 of human c-Myb by MAP kinase". Biol. Chem. 377 (11): 721–30. doi:10.1515/bchm3.1996.377.11.721. PMID8960373.
Leverson JD, Koskinen PJ, Orrico FC, Rainio EM, Jalkanen KJ, Dash AB, Eisenman RN, Ness SA (1998). "Pim-1 kinase and p100 cooperate to enhance c-Myb activity". Mol. Cell. 2 (4): 417–25. doi:10.1016/S1097-2765(00)80141-0. PMID9809063.
Thompson MA, Rosenthal MA, Ellis SL, Friend AJ, Zorbas MI, Whitehead RH, Ramsay RG (1998). "c-Myb down-regulation is associated with human colon cell differentiation, apoptosis, and decreased Bcl-2 expression". Cancer Res. 58 (22): 5168–75. PMID9823328.
Verbeek W, Gombart AF, Chumakov AM, Müller C, Friedman AD, Koeffler HP (1999). "C/EBPepsilon directly interacts with the DNA binding domain of c-myb and cooperatively activates transcription of myeloid promoters". Blood. 93 (10): 3327–37. PMID10233885.
