M33 is a gene. [1] It is a mammalian homologue of Drosophila Polycomb. [1] It localises to euchromatin within interphase nuclei, but it is enriched within the centromeric heterochromatin of metaphase chromosomes. [1] In mice, the official symbol of M33 gene styled Cbx2 and the official name chromobox 2 are maintained by the MGI. Also known as pc; MOD2. In human ortholog CBX2, synonyms CDCA6, M33, SRXY5 from orthology source HGNC. M33 was isolated by means of the structural similarity of its chromodomain. [2] It contains a region of homology shared by Xenopus and Drosophila in the fifth exon. [3] Polycomb genes in Drosophila mediate changes in higher-order chromatin structure to maintain the repressed state of developmentally regulated genes . [4] [5] It may also involved in the campomelic syndrome and neoplastic disorders linked to allele loss in this region. [6] Disruption of the murine M33 gene, displayed posterior transformation of the sternal ribs and vertebral columns . [7]
The mouse M33 gene is located on the Chromosome 11, from base pair 119,022,962 to base pair 119,031,270 (Build GRCm38/mm10). Human homolog of M33, Chromobox homolog 2 (CBX2 ) is located on Chromosome 17, from base pair 79,777,188 to base pair 79,787,650(Build GRCh38.p2).
This protein contains Chromo (CHRromatin Organization MOdifier) domain and nuclear localization signal motif. [8] The full-length M33 sequence encodes a 519 amino acid (aa) protein. [2]
The mouse Polycomb group (PcG) protein M33 maintains repressed states of developmentally important genes, including homeotic genes and forms nuclear complexes with other PcG members. e.g.BMI1. [9] It also direct and/or indirect controls the vicinity of Hox genes regulatory regions, which are the accessibility of retinoic acid response elements . [10] homeotic transformations of the axial skeleton, and growth retardation. [11] [12] Moreover, the deficient of M33 also possessed abnormally few nucleated cells in the thymus and spleen, due to the aberrant T-cell expansion. [13] In transiently transfected cells, M33 acts as a transcriptional repressor . Biochemical assays indicate that two murine proteins, Ring1A [14] and Ring1B [14] interact directly with the repressor domain of M33 and that Ring1A can also behave as a transcriptional repressor. [15]
Flamingo is a member of the adhesion-GPCR family of proteins. Flamingo has sequence homology to cadherins and G protein-coupled receptors (GPCR). Flamingo was originally identified as a Drosophila protein involved in planar cell polarity. Mammals have three flamingo homologs, CELSR1, CELSR2, CELSR3. In mice all three have distinct expression patterns in the brain.
Polycomb-group proteins are a family of protein complexes first discovered in fruit flies that can remodel chromatin such that epigenetic silencing of genes takes place. Polycomb-group proteins are well known for silencing Hox genes through modulation of chromatin structure during embryonic development in fruit flies. They derive their name from the fact that the first sign of a decrease in PcG function is often a homeotic transformation of posterior legs towards anterior legs, which have a characteristic comb-like set of bristles.
Chromobox protein homolog 1 is a protein that in humans is encoded by the CBX1 gene.
Chromobox protein homolog 3 is a protein that is encoded by the CBX3 gene in humans.
Polycomb complex protein BMI-1 also known as polycomb group RING finger protein 4 (PCGF4) or RING finger protein 51 (RNF51) is a protein that in humans is encoded by the BMI1 gene. BMI1 is a polycomb ring finger oncogene.
Transcription factor HES1 is a protein that is encoded by the Hes1 gene, and is the mammalian homolog of the hairy gene in Drosophila. HES1 is one of the seven members of the Hes gene family (HES1-7). Hes genes code nuclear proteins that suppress transcription.
E3 ubiquitin-protein ligase RING2 is an enzyme that in humans is encoded by the RNF2 gene.
Polycomb protein EED is a protein that in humans is encoded by the EED gene.
Polyhomeotic-like protein 1 is a protein that in humans is encoded by the PHC1 gene.
Polycomb group RING finger protein 2, PCGF2, also known as MEL18 or RNF110, is a protein that in humans is encoded by the PCGF2 gene.
Enhancer of polycomb homolog 1 is a protein that in humans is encoded by the EPC1 gene.
Polyhomeotic-like protein 2 is a protein that in humans is encoded by the PHC2 gene.
Chromobox protein homolog 5 is a protein that in humans is encoded by the CBX5 gene. It is a highly conserved, non-histone protein part of the heterochromatin family. The protein itself is more commonly called HP1α. Heterochromatin protein-1 (HP1) has an N-terminal domain that acts on methylated lysines residues leading to epigenetic repression. The C-terminal of this protein has a chromo shadow-domain (CSD) that is responsible for homodimerizing, as well as interacting with a variety of chromatin-associated, non-histone proteins.
Polycomb group RING finger protein 6 is a protein that in humans is encoded by the PCGF6 gene.
Protein Jumonji is a protein that in humans is encoded by the JARID2 gene. JARID2 is a member of the alpha-ketoglutarate-dependent hydroxylase superfamily.
Chromobox protein homolog 8 is a protein that in humans is encoded by the CBX8 gene.
Putative Polycomb group protein ASXL1 is a protein that in humans is encoded by the ASXL1 gene.
Chromobox protein homolog 2 is a protein that in humans is encoded by the CBX2 gene.
Polycomb group RING finger protein 1, PCGF1, also known as NSPC1 or RNF68 is a RING finger domain protein that in humans is encoded by the PCGF1 gene.
The gene Maelstrom, Mael, creates a protein, which was first located in Drosophila melanogaster in the nuage perinuclear structure and has functionality analogous to the spindle, spn, gene class. Its mammalian homolog is MAEL.