Transmembrane protein 261 is a protein that in humans is encoded by the TMEM261 gene located on chromosome 9 .[1] TMEM261 is also known as C9ORF123 and DMAC1 , Chromosome 9 Open Reading Frame 123 and Transmembrane Protein C9orf123[2] and Distal membrane-arm assembly complex protein 1[3] .
Gene Features
TMEM261 is located at 9p24.1, its length is 91,891 base pairs (bp) on the reverse strand.[2] Its neighbouring gene is PTPRD located at 9p23-p24.3 also on the reverse strand and encodes protein tyrosine phosphatase receptor type delta.[1] [2]
TMEM261 has 2 exons and 1 intron , and 6 primary transcript variants; the largest mRNA transcript variant consisting of 742bp with a protein 129 amino acids (aa) in length and 13,500 Daltons (Da) in size, and the smallest coding transcript variant being 381bp with a protein 69aa long and 6,100 Da in size.[4] [5]
File:TMEM261 features.jpg Annotated features of TMEM261 protein including topology and important sites for phosphorylation and Myristoylation as well DUF4536 and transmembrane helical domains.
Protein Features
TMEM261 is a protein consisting out of 112 amino acids, with a molecular weight of 11.8 kDa.[6] The isoelectric point is predicted to be 10.2,[7] whilst its posttranslational modification value is 9.9.[5]
Structure
File:TMEM261interactions.jpg Some proteins found to interact with TMEM261
TMEM261 contains a domain of unknown function , DUF4536 (pfam15055), predicted as a helical membrane spanning domain about 45aa (Cys 47- Ser 92) in length with no known domain relationships.[8] [9] Two further transmembrane helical domains are predicted of lengths 18aa (Val 52-Ala 69) and 23aa (Pro 81-Ala 102]).[10] [11] There is also a low complexity region spanning 25aa (Thr 14-Ala 39).[12] The tertiary structure for TMEM261 has not yet been determined. However, its protein secondary structure is mostly composed of coiled-coil regions with beta strands and alpha helices found within the transmembrane and domain of unknown function regions. The N-terminal region of TMEM261 is composed of a disordered region[13] [14] which contains the low complexity region[12] that is not highly conserved amongst orthologues.[15] [16]
Modifications
A N-myristoylation domain is shown to be present in most TMEM261 protein variants.[5] Post-translational modifications include myristoylation of the N-terminal Glycine residue (Gly 2)[5] [17] of the TMEM261 protein as well as phosphorylation of Threonine 31.[18]
Interactions
Proteins shown to interact with TMEM261 include NAAA (protein-protein interaction ), QTRT1 (RNA-protein interaction ),ZC4H2 (DNA-protein interaction )[19] and ZNF454 (DNA-protein interaction).[20] [21] It has also shown to interact with APP (protein-protein interaction),[22] ARHGEF38 (protein-protein interaction)[23] and HNRNPD (RNA-protein interaction ).[24] [25]
File:Tissueexpression.jpg Tissue expression of TMEM261 showing tissue enriched gene (TEG) expression [26] Additional transcription factor binding sites (DNA-protein interaction) predicted include one binding site for MEF2C a monocyte -specific enhancement factor that is involved in muscle-cell regulation particularly in the cardiovascular system [2] [27] and two binding sites for GATA1 which is a globin transcription factor 1 involved in erythroblast development regulation.[28] [29] [30]
Expression
TMEM261 shows ubiquitous expression in humans and is detected in almost all tissue types.[31] [32] It shows tissue-enriched gene (TEG) expression when compared to housekeeping gene (HKG) expression.[26] Its highest expression is seen in the heart (overall relative expression 94%) particularly in heart fibroblast cells, thymus (overall relative expression 90%), and thyroid (overall relative expression 93%) particularly in thyroid glandular cells.[26] [31] Staining intensity of cancer cells showed intermediate to high expression in breast , colorectal , ovarian , skin , urothelial , head and neck cells.[31]
Function
Currently the function for TMEM261 is unknown.[33] However, gene amplification and rearrangements of its locus have been associated with various cancers including colorectal cancer ,[34]
breast cancer [35] and lymphomas .[36] [37]
Evolution
Orthologues
The orthologues and homologues of TMEM261 are limited to vertebrates , its oldest homologue dates to that of the cartilaginous fishes [38] which diverged from Homo sapiens 462.5 million years ago.[39] The protein primary structure of TMEM261 shows higher overall conservation in mammals , however high conservation of the domain of unknown function (DUF4536) to the C-terminus region is seen in all orthologues, including distant homologues. The protein structure of TMEM261 shows conservation across most orthologues.[15] [16]
Paralogues
TMEM261 has no known paralogs.[38]
References
↑ 1.0 1.1 "Entrez Protein: TMEM261" .
↑ 2.0 2.1 2.2 2.3 "GeneCards: PTPRD" .
↑ "DMAC1 - Distal membrane-arm assembly complex protein 1 - Homo sapiens (Human) - DMAC1 gene & protein" . www.uniprot.org . Retrieved 2018-07-30 .
↑ Thierry-Mieg, D; Thierry-Mieg, J. (2006). "AceView: a comprehensive cDNA-supported gene and transcripts annotation" . Genome Biology . 7 (Suppl 1): S12. doi :10.1186/gb-2006-7-s1-s12 . PMC 1810549 . PMID 16925834 .
↑ 5.0 5.1 5.2 5.3 "AceView:Homo sapiens gene C9orf123" .
↑ "Ensemble:Transcript TMEM261-003" .
↑ "PI:Isoelectric point determination" .
↑ "NCBI Conserved Domains: DUF4536" .
↑ "EMBL-EBI Interpro: Transmembrane protein 261 (Q96GE9)" .
↑ "Phobius: A combined transmembrane topology and signal peptide predictor" .
↑ "Q96GE9 - TM261_HUMAN" . UniProt . UniProt Consortium.
↑ 12.0 12.1 "Vega: Transcript: C9orf123-003" .
↑ "PHYRE: Protein Homology/analogY Recognition Engine" . PHYRE .
↑ Kelley, LA; Sternberg, MJE (2009). "Protein structure prediction on the Web: a case study using the Phyre server" . MJE . 4 : 363–371. doi :10.1038/nprot.2009.2 . PMID 19247286 .
↑ 15.0 15.1 "ClustalW" .
↑ 16.0 16.1 Thompson, Julie D; Higgins, Desmond G; Gibson, Toby J (1994). "CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choice" . Nucleic Acids Res . 22 (22): 4673–4680. doi :10.1093/nar/22.22.4673 . PMC 308517 . PMID 7984417 .
↑ Gallo, Vincenzo. "Myristoylation : Proteins Post-translational Modifications" . flipper.diff.org . University of Turin.
↑ "Nextprot:TMEM261 » Transmembrane protein 261" .
↑ Dash A, et al. (2002). "Changes in differential gene expression because of warm ischemia time of radical prostatectomy specimens" . Am J Pathol . 161 (5): 1743–1748. doi :10.1016/S0002-9440(10)64451-3 . PMC 1850797 . PMID 12414521 .
↑ Rovillain E, et al. (2011). "An RNA interference screen for identifying downstream effectors of the p53 and pRB tumour suppressor pathways involved in senescence" . BMC Genomics . 12 (355). doi :10.1186/1471-2164-12-355 . PMC 3161017 . PMID 21740549 .
↑ "c9orf123 protein (Homo Sapiens)- STRING Network View" . STRING - Known and Predicted Protein-Protein Interactions .
↑ Oláh J, et al. (2011). "Interactions of pathological hallmark proteins: tubulin polymerization promoting protein/p25, beta-amyloid, and alpha-synuclein" . J Biol Chem . 286 (39): 34088–34100. doi :10.1074/jbc.M111.243907 . PMC 3190826 . PMID 21832049 .
↑ Huttlin EL, et al. (2014). "High-Throughput Proteomic Mapping of Human Interaction Networks via Affinity-Purification Mass Spectrometry (Pre-Publication)" . Pre-Publication .
↑ Lehner, B; Sanderson, C M (2004). "A protein interaction framework for human mRNA degradation" . Genome Res . 14 (7): 1315–1323. doi :10.1101/gr.2122004 . PMC 442147 . PMID 15231747 .
↑ "9ORF123 chromosome 9 open reading frame 123" . BioGRID: Database of Protein and Genetic Interactions . TyersLab.
↑ 26.0 26.1 26.2 She X, Rohl CA, Castle JC, Kulkarni AV, Johnson JM, Chen R (2009). "Definition, conservation and epigenetics of housekeeping and tissue-enriched genes" . BMC Genomics . 10 : 269. doi :10.1186/1471-2164-10-269 . PMC 2706266 . PMID 19534766 .
↑ "GeneCards:MEF2C Gene" .
↑ Welch JJ, et al. (2004). "Global regulation of erythroid gene expression by transcription factor GATA-1" . Blood . 104 (10): 3136–3147. doi :10.1182/blood-2004-04-1603 . PMID 15297311 .
↑ Merryweather-Clarke AT, et al. (2011). "Global gene expression analysis of human erythroid progenitors" . Blood . 117 (13): e96–108. doi :10.1182/blood-2010-07-290825 . PMID 21270440 .
↑ "Genomatics- NGS Data Analysis and Personalised Medicine" . Genomatix . Genomatix Software GmbH.
↑ 31.0 31.1 31.2 "The Human Protein Atlas:TMEM261" .
↑ "EST profile: TMEM261" . UniGene . National Library of Medicine.
↑ Wu J, et al. (2012). "Identification and functional analysis of 9p24 amplified genes in human breast cancer" . Oncogene . 31 (3): 333–341. doi :10.1038/onc.2011.227 . PMC 3886828 . PMID 21666724 .
↑ Gaspar, C (2008). "Cross-Species Comparison of Human and Mouse Intestinal Polyps Reveals Conserved Mechanisms in Adenomatous Polyposis Coli (APC)-Driven Tumorigenesis" . Am J Pathol . 172 (5): 1363–1380. doi :10.2353/ajpath.2008.070851 . PMC 2329845 . PMID 18403596 .
↑ Wu, J (2012). "Identification and functional analysis of 9p24 amplified genes in human breast cancer" . Oncogene . 31 (3): 333–341. doi :10.1038/onc.2011.227 . PMC 3886828 . PMID 21666724 .
↑ Twa DD, et al. (2014). "Genomic Rearrangements Involving Programmed Death Ligands Are Recurrent in Primary Mediastinal Large B-Cell Lymphoma" . Blood . 123 (13): 2062–2065. doi :10.1182/blood-2013-10-535443 . PMID 24497532 .
↑ Green MR, et al. (2010). "Integrative Analysis Reveals Selective 9p24.1 Amplification, Increased PD-1 Ligand Expression, and Further Induction via JAK2 in Nodular Sclerosing Hodgkin Lymphoma and Primary Mediastinal Large B-Cell Lymphoma" . Blood . 116 (17): 3268–3277. doi :10.1182/blood-2010-05-282780 . PMC 2995356 . PMID 20628145 .
↑ 38.0 38.1 "NCBI BLAST:Basic Local Alignment Search Tool" .
↑ Hedges, S. Blaire; Dudley, Joel; Kumar, Sudhir (22 September 2006). "TimeTree: a public knowledge-base of divergence times among organisms" (PDF) . Bioinformatics . 22 (23): 2971–2972. doi :10.1093/bioinformatics/btl505 . PMID 17021158 .
External links
Further reading
Nicholas K. Tonks (2006). "Protein tyrosine phosphatases: from genes, to function, to disease". Cancer Cell . 7 : 833–846. doi :10.1038/nrm2039 .
Merryweather-Clarke AT, et al. (2011). "Global gene expression analysis of human erythroid progenitors". Blood . 117 (13): e96–108. doi :10.1182/blood-2010-07-290825 . PMID 21270440 .
Welch JJ, Watts JA, Vakoc CR, et al. (2004). "Global regulation of erythroid gene expression by transcription factor GATA-1". Blood . 104 (10): 3136–3147. doi :10.1182/blood-2004-04-1603 . PMID 15297311 .
Nickeleit I, et al. (2008). "Argyrin a reveals a critical role for the tumor suppressor protein p27(kip1) in mediating antitumor activities in response to proteasome inhibition". Cancer Cell . 14 (1): 23–35. doi :10.1016/j.ccr.2008.05.016 . PMID 18598941 .