Maestro heat-like repeat family member 6 (MROH6), also known as c8orf73, is a protein which in humans is encoded by the MROH6 gene. [1] The word 'maestro' itself is an acronym, standing for Male-Specific Transcription in the Developing Reproductive Organs (MRO). MRO genes belong to the MROH family, which includes MROH1, MROH2B, MROH7, MROH8, and MROH9. [2]
The genomic location of MROH6 in humans is on chromosome 8 (8q24.3), spanning 6,581 base pairs, from base pair 143,566,192 to 143,572,772. The gene contains a total of 15 exons. [1]
The MROH6 gene encodes 17 known mRNA transcript variants. The longest transcript variant is simply referred to as MROH6, which is 3,265 nucleotides long and contains 14 exons. [1]
| Transcript variant number | Accession number | Span in nucleotides | Aligned length in nucleotides | Exons used |
|---|---|---|---|---|
| MROH6 | NM_001100878.2 | 6,581 | 3,265 | 14 |
| X1 | XM_011517214.2 | 6,581 | 2,641 | 14 |
| X2 | XM_011517215.2 | 6,581 | 2,638 | 14 |
| X3 | XM_011517216.3 | 6,581 | 2,573 | 13 |
| X4 | XM_011517217.2 | 6,581 | 2,507 | 12 |
| X5 | XM_011517220.2 | 4,974 | 2,223 | 11 |
| X6 | XM_011517221.3 | 6,334 | 2,159 | 15 |
| X7 | XM_047422089.1 | 6,334 | 2,156 | 15 |
| X8 | XM_011517222.2 | 6,581 | 2,338 | 14 |
| X9 | XM_047422090.1 | 6,333 | 2,140 | 15 |
| X10 | XM_047422092.1 | 6,581 | 2,317 | 14 |
| X11 | XM_011517223.2 | 6,581 | 2,272 | 13 |
| X12 | XM_047422093.1 | 6,581 | 2,269 | 14 |
| X13 | XM_047422094.1 | 6,581 | 2,254 | 13 |
| X14 | XM_047422095.1 | 6,581 | 2,251 | 13 |
| X15 | XM_047422096.1 | 6,581 | 2,197 | 13 |
| X16 | XM_006716615.3 | 4,987 | 2,263 | 11 |
| X17 | XM_047422097.1 | 4,987 | 2,260 | 11 |
The protein encoded by the primary isoform of MROH6 is 719 amino acids long. [1]
A notable feature of the MROH6 protein is the presence of seven HEAT repeats, which are protein tandem repeat structural motifs. HEAT repeats are composed of two alpha helices linked by a short loop. These repeats give MROH6 and its gene family its name, as well as directing the function of the protein. [3]
MROH6 consists primarily of alpha helices. The protein structure lacks any beta sheets. [4]
MROH6 demonstrates broad expression throughout the human body. However, it shows noticeably higher expression in certain tissues, such as the esophagus. In human fetal development, high expression is shown in the stomach, lung, intestine, and adrenal gland. RNA sequencing data also shows high expression in the cerebellum, liver, lung, placenta, small intestine, and stomach. The Human Protein Atlas indicates high expression in the bone marrow, esophagus, skin, and stomach. [5]
The protein is predicted to be localized within the cytoplasm, nucleus, and mitochondria. [6]
Orthologs of the MROH6 protein were found to exist in amniotes as well as the genome of Amia calva . Despite the presence of the gene in Amia calva, orthologs of MROH6 have not been found in any other fish nor in amphibians.
| Scientific name | Common name | Taxon | median date of divergence (MYA) | Accession # | Length (amino acids) | % identity to humans | % similarity to humans |
|---|---|---|---|---|---|---|---|
| Homo Sapiens | Humans | Primates | 0.0 | NP_001094348.1 | 719 | 100.0% | 100.0% |
| Theropithecus gelada | Gelada | Primates | 28.8 | XP_025250353.1 | 717 | 95.5% | 96.9% |
| Mus musculus | House mouse | Rodentia | 87.0 | NP_001269372.1 | 722 | 79.8% | 85.6% |
| Ursus maritimus | Polar bear | Carnivora | 94.0 | XP_040481956.1 | 705 | 79.5% | 84.4% |
| Bos taurus | Common cattle | Artiodactyl | 94.0 | XP_002692603.1 | 711 | 79.8% | 84.6% |
| Manis javanica | Malayan pangolin | Pholidota | 94.0 | KAI5929482.1 | 691 | 74.2% | 80.2% |
| Elephas maximus indicus | Indian elephant | Elephantidae | 99.0 | XP_049709696.1 | 717 | 80.8% | 85.8% |
| Sarcophilus harrisii | Tasmanian devil | Marsupialia | 160.0 | XP_031803182.1 | 735 | 57.9% | 66.7% |
| Ornithorhynchus anatinus | Platypus | Monotremes | 180.0 | XP_039767867.1 | 832 | 51.3% | 58.9% |
| Gallus gallus | Red junglefowl | Galliformes | 319.0 | XP_040537654.1 | 651 | 23.8% | 37.7% |
| Anas platyrhynchos | Mallard | Anseriformes | 319.0 | XP_071898069.1 | 736 | 20.4% | 32.6% |
| Falco naumanni | Lesser kestrel | Falconiformes | 319.0 | XP_040449421.1 | 583 | 20.7% | 32.7% |
| Patagioenas fasciata | Band-tailed pigeon | Columbiformes | 319.0 | XP_071666853.1 | 857 | 22.7% | 33.6% |
| Colius striatus | Speckled mousebird | Coliiformes | 319.0 | XP_061870785.1 | 581 | 22.0% | 32.9% |
| Candoia aspera | Papuan ground boa | Serpentes | 319.0 | XP_063156074.1 | 775 | 33.2% | 47.0% |
| Tiliqua scincoides | Common blue-tongued skink | Scincidae | 319.0 | XP_066477445.1 | 734 | 24.3% | 37.4% |
| Chelonia mydas | Green sea turtle | Cryptodira | 319.0 | XP_027683785.3 | 885 | 32.0% | 42.4% |
| Emydura macquarii macquarii | Macquarie River turtle | Pleurodira | 319.0 | XP_067392966.1 | 372 | 19.2% | 27.3% |
| Crocodylus porosus | Saltwater crocodile | Crocodilians | 319.0 | XP_019406236.1 | 169 | 6.4% | 9.6% |
| Amia calva | Ruddy bowfin | Actinopterygii | 429.0 | XP_066543890.1 | 168 | 7.2% | 10.9% |
MROH6 has multiple paralogs found in the human genome and is a member of the MROH family, consisting of seven other genes, as well as three pseudogenes. [2]
| Paralog | Accession # | Length (amino acids) | Percent identity to MROH6 | Percent similarity to MROH6 |
|---|---|---|---|---|
| MRO | NP_114145 | 248 | 7.9% | 12.5% |
| MROH1 | NP_115826.3 | 1,641 | 12.0% | 16.9% |
| MROH2A | NP_001381568.1 | 1,674 | 10.2% | 17.0% |
| MROH2B | NP_775760.3 | 1,585 | 10.3% | 17.0% |
| MROH7 | NP_001034553.3 | 1,323 | 16.0% | 23.7% |
| MROH8 | NP_689716.4 | 1,052 | 15.8% | 27.0% |
| MROH9 | NP_001157101.1 | 861 | 18.3% | 31.1% |
The MROH6 protein has been shown and predicted to interact with a wide variety of proteins with a wide variety of functions and localization. These include NUDT15, XPO1, NMNAT1, NMNAT2, NMNAT3, NAPRT, FTL, IQGAP1, SMCO3, NADSYN1, and FAAH. [9] [10] [11] [12]
Little research has been done into MROH6. MROH6 has been identified as a possible contributor to neuroblastoma, with high expression of the protein leading to poor prognosis. [13] Other studies have identified changes in MROH6 expression as a possible contributor to male infertility, changes in interleukin-18 levels, and gestational diabetes mellitus. [14] [15] [16]