TMTC4

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TMTC4
Identifiers
AliasesTMTC4, transmembrane and tetratricopeptide repeat containing 4, transmembrane O-mannosyltransferase targeting cadherins 4
External IDsOMIM: 618203 MGI: 1921050 HomoloGene: 32796 GeneCards: TMTC4
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

NM_028651
NM_001360598
NM_001360599

RefSeq (protein)

NP_082927
NP_001347527
NP_001347528

Location (UCSC)Chr 13: 100.6 – 100.68 MbChr 14: 122.92 – 122.98 Mb
PubMed search[3][4]
Wikidata
View/Edit HumanView/Edit Mouse

Transmembrane and Tetratricopeptide repeat containing 4 is a protein that in humans is encoded by the TMTC4 gene.[5] This protein crosses the plasma membrane 10 times, and resides in the ER lumen and cytosol. The predicted structure of the TMTC4 protein is a series of alpha-helices.

Gene[edit]

TMTC4 is located on chromosome 13 at 13q32.3. The gene is flanked by ADP ribosylation factor 4 pseudogene 3 (ARF4P3) on the left, and ribosomal protein S26 pseudogene 47 (RPS26P47) on the right. TMTC4 spans 4043 bp and has a total of 23 exons.[5]

mRNA[edit]

TMTC4 has seven isoform variants, the most common being isoform 1 at 4043 bp.[5]

Isoform Length (bp)
1 4043
2 3833
3 3500
4 4217
5 4120
6 4037
7 3827

The 5’ UTR for TMTC4 is short and in many of the shorter isoforms, portions of this untranslated region are cut. In comparison, the 3’ UTR is long and is often complete across the seven isoforms.

Protein[edit]

Physical properties[edit]

The molecular weight for TMTC4 is 85.0 kdal, and there are no positive, negative, or neutral clusters of amino acids or charge runs exceeding the normal lengths. When looking at a distant ortholog (purple sea urchin) the molecular weight of TMTC4 is 85.5 kdal and there, again, are no charge runs, positive, negative or neutral clusters, or unusual spacings. There are strong similarities in protein composition across species. The isoelectric point for the domain of unknown function (DUF 1736) is lower than that of the protein overall.

Schematic illustration of known and predicted domains and motifs for TMTC4
Domain Amino Acids Molecular Weight (kdal) Isoelectric Point
Human TMTC4 760 85.0 9.135
DUF 1736 75 8.6 4.123
TPR repeats 234 26.7 9.509

Domains[edit]

Predicted secondary structure of TMTC4. Starting at blue and going to red, the diagram illustrates the n-terminus through the c-terminus.

TMTC4 has ten transmembrane regions, all of them spaced within the first half of the protein.[6]

TMTC4 is layered with tetratricopeptide (TPR) repeat sequences that are a part of the TPR superfamily of proteins. DUF1736 is present upstream of the TPR region. A seven residue repeat (SRR) is located toward the end of the protein, and it is thought to encode a coiled-coil structure.[7] Another member of the TPR family, PFTA (protein prenyltransferases alpha subunit repeat), is located within the protein's TPR region and is believed to be involved in signal transduction and vesicular traffic regulation.[8] LSPR coagulation factor V, also a repeat motif, is located within the TPR region, and is thought to be a central regulator of hemostasis.[9]

Secondary structure[edit]

TMTC4 takes on a series of alpha-helix structures, especially within the TPR region, though there are a minimal amount of beta-strand structures spaced throughout the beginning half of the protein.[10]

Post-translational modifications[edit]

Predicted post-translational modifications of TMTC4 protein

There are four predicted nuclear localization signals, each tagging the protein for nuclear import.[6] At the very end of the protein, however, there is a predicted ER retention signal which would prevent the protein from leaving the ER. The protein has three predicted N-glycosylation sites, potentially altering its structure and function and there are ten predicted phosphorylation sites, each a possible activation site for a regulatory mechanism.[6]

Expression[edit]

TMTC4 is expressed in all human tissues. The gene, however, is most highly expressed in the brain and in the spinal cord.[11]

Protein abundance seems to be lower than normal for TMTC4.

Regulation[edit]

There is one possible promoter for the TMTC4 gene, located in the 5’ UTR but before the start of the coding sequence.

Function[edit]

Currently the function of TMTC4 has not been characterized.

Interacting proteins[edit]

Possible interacting proteins are NRG1, PEX19, HERC3, TXNDC15, and COL1A1 . All of these were detected through affinity chromatography.[12]

Protein Name Known function Location
Neuregulin 1 [NRG1] mediates cell to cell signaling[13] membrane glycoprotein[13]
Peroxisomal Biogenesis Factor 19 [PEX19] cytosolic chaperone[14] membrane receptor protein[14]
ECT And RLD Domain Containing E3 Ubiquitin Protein Ligase 3 [HERC3] member of the ubiquitin ligase family[15] cytosol[15]
Thioredoxin Domain Containing 15 [TXNDC15] Not known Not known
Collagen Type I Alpha 1 Chain [COL1A1] triple helix collagen protein[16] extracellular[16]

Homology[edit]

Orthologs[edit]

Ortholog space for TMTC4 spans a large portion of evolutionary time. TMTC4 is present in mammals, reptiles, amphibians, birds, fish, and invertebrates. It is not present in plants, bacteria, archaea, or fungi.[17]

Sequence Number Genus and Species Common Name Accession # (protein) Identity Date of Divergence (MYA)
1 Heterocephalus glaber Naked mole rat EHB03258.1 88% 94
2 Rattus norvegicus Brown rat NP_001127886.1 90% 94
3 Myotis brandtii Brandt's bat EPQ01527.1 90% 94
4 Pteropus alecto Black flying fox XP_006909447.1 93% 88
5 Erinaceus europaeus European hedgehog XP_016040457.1 85% 94
6 Sorex araneus Common shrew XP_004614101.1 86% 94
7 Sus scrofa Wild boar NP_001239134.1 91% 94
8 Lipotes vexillifer Baiji XP_007461591.1 90% 88
9 Ailuropoda melanoleuca Giant panda XP_019650336.1 90% 94
10 Acinonyx jubatus Cheetah XP_014931490.1 93% 94
11 Tyto alba Barn owl KFV56414.1 85% 320
12 Charadrius vociferus Killdeer KGL87053.1 84% 320
13 Python bivittatus Burmese python XP_007425712.1 81% 320
14 Anolis carolinensis Carolina anole XP_008105174.1 82% 320
15 Xenopus tropicalis Western clawed frog NP_001121486.1 38% 353
16 Nanorana parkeri Nanorana parkeri XP_018432106.1 73% 353
17 Callorhinchus milii Australian ghostshark XP_007885231.1 68% 465
18 Crassostrea gigas Pacific oyster XP_011422949.1 50% 758
19 Strongylocentrotus purpuratus Purple sea urchin XP_011670776.1 49% 627

Paralogs[edit]

Paralog space for TMTC4 spans the gene family TMTC. There are four genes in this gene family: TMTC1, TMTC2, TMTC3, and TMTC4. TMTC1 and TMTC3 split from TMTC4 about 1200 million years ago, while TMTC2 split from TMTC4 1400 million years ago. Both of these events happened somewhere between invertebrates and plants.

References[edit]

  1. ^ a b c GRCh38: Ensembl release 89: ENSG00000125247Ensembl, May 2017
  2. ^ a b c GRCm38: Ensembl release 89: ENSMUSG00000041594Ensembl, May 2017
  3. ^ "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  4. ^ "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  5. ^ a b c "TMTC4 transmembrane and tetratricopeptide repeat containing 4". Entrez Gene.
  6. ^ a b c "Motif Scan". Swiss Institute of Bioinformatics. Retrieved 2017-05-04.
  7. ^ Grigoryan G, Keating AE (2008). "Structural specificity in coiled-coil interactions". Current Opinion in Structural Biology. 18 (4): 477–83. doi:10.1016/j.sbi.2008.04.008. PMC 2567808. PMID 18555680.
  8. ^ Zhang H, Grishin NV (August 1999). "The alpha-subunit of protein prenyltransferases is a member of the tetratricopeptide repeat family". Protein Science. 8 (8): 1658–67. doi:10.1110/ps.8.8.1658. PMC 2144414. PMID 10452610.
  9. ^ "Coagulation factor V, LSPD (IPR009271)". InterPro. EMBL-EBI. Retrieved 2017-04-27.
  10. ^ "I-TASSER results". I-TASSER. University of Michigan. Retrieved 2017-04-27.
  11. ^ "2906582". GEO Profiles. NCBI. Retrieved 2017-04-27.
  12. ^ Huttlin EL, Ting L, Bruckner RJ, Gebreab F, Gygi MP, Szpyt J, et al. (July 2015). "The BioPlex Network: A Systematic Exploration of the Human Interactome". Cell. 162 (2): 425–40. doi:10.1016/j.cell.2015.06.043. PMC 4617211. PMID 26186194.
  13. ^ a b "NRG1 Gene". GeneCards. Retrieved 2017-04-27.
  14. ^ a b "PEX19 Gene". GeneCards. Retrieved 2017-04-27.
  15. ^ a b "HERC3 Gene". GeneCards. Retrieved 2017-04-27.
  16. ^ a b "COL1A1 Gene". GeneCards. Retrieved 2017-04-27.
  17. ^ "BLAST: Basic Local Alignment Search Tool". NCBI. Retrieved 2017-04-27.

Further reading[edit]