| transmembrane protein 53 | |
| Hgncid: | 26186 |
| Symbol: | TMEM53 |
| Altsymbols: | FLJ22353, RP4-678E16.2 |
| Entrezgene: | 79639 |
| Refseq: | NP_078863 |
| Uniprot: | Q6P2H8 |
| Chromosome: | 1 |
| Arm: | p |
| Band: | 34.1 |
Transmembrane protein 53, or TMEM53, is a protein that is encoded on chromosome 1 in humans.[1] It has no paralogs but is predicted to have many orthologs across eukaryotes.
The secondary structure of TMEM53 is predicted to consist of alternating pairs of alpha helices and beta sheets.[2]
TMEM53 has 3 exons. Twelve alternative splice forms have been identified using 26 alternative exons.[3] The following table includes the predicted post-translational modifications for each isoform.
| AceView Splice Form |
| % ID with RefSeq |
| DUF829 | CK2 sites | PKC sites | Tyr sites | Pumilio site | N-Myristoylation sites | Extras (not comparable to RefSeq) | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| a | 277 | RefSeq | 64 | X | 2 | 3 | 1 | 1 | 2 | ||
| b | 247 | 88.8% | 6 | X | 2 | 2 | 1 | 1 | 2 | ||
| c | 204 | 64.4% | 1 | X | 2 | 1 | 1 | 1 | 2 | Microbody C-terminal targeting signal | |
| d | 204 | 73.6% | 10 | X | 2 | 2 | 1 | 1 | 1 | ||
| e | 223 | 57.5% | 2 | X | 1 | 4 | 3 | ||||
| f | 143 | 21.4% | 1 | X | 1 | 3 | 3 | Amidation site, Asn glycosylation site, cAMP-dependent phosphorylation site | |||
| g | 142 | n/a | 1 | 1 | 3 | 1 | |||||
| h | 137 | 45.1% | 2 | X | 1 | 3 | 2 | Protein prenyltransferase repeat | |||
| i | 129 | 32.1% | 1 | X | 4 | 2 | |||||
| j | 139 | 27.2% | 21 | X | 2 | 3 | |||||
| k | 110 | n/a | 1 | 1 | 4 | 3 | Amidation site, Asn glycosylation site, cAMP-dependent phosphorylation site | ||||
| l | 106 | n/a | 5 | 3 |
The function of TMEM53 is not fully understood. It contains a domain of unknown function, DUF829, which is approximately 240 amino acids long. This domain has not been found in proteins other than TMEM53 and its orthologs.
Based on human and mouse EST profiles and a human tissue GEO profile, TMEM53 appears to be expressed ubiquitously at low levels in both normal and cancerous tissues.[4] [5] [6]
More specific expression patterns have also been observed:
Transmembrane protein 53 has no paralogs. It does, however, have orthologs extending throughout eukaryotes, from primates to amoeba. The following table presents a selection of orthologs found using searches in BLAST[10] and BLAT.[11] It is not a comprehensive list, but rather a small selection meant to display the diversity of species in which orthologs are found.
| Scientific Name | Common Name | Accession Number | Sequence Length | Percent Identity | Percent Similarity | |
|---|---|---|---|---|---|---|
| Homo sapiens | Human | NP_078863 | 277 aa | - | - | |
| Macaca mulatta | Rhesus monkey | XP_001093396.1 | 204 aa | 97% | 98% | |
| Canis lupus familiaris | Dog | XP_539639.2 | 278 aa | 88% | 92% | |
| Mus musculus | Mouse | NP_081113.1 | 276 aa | 86% | 91% | |
| Monodelphis domestica | Opossum | XP_001376124.1 | 405 aa | 69% | 82% | |
| Gallus gallus | Chicken | XP_422420.1 | 276 aa | 56% | 70% | |
| Xenopus laevis | Frog | NP_001086490.1 | 285 aa | 54% | 69% | |
| Danio rerio | Zebrafish | NP_001002637.1 | 281 aa | 47% | 66% | |
| Ciona intestinalis | Sea squirt | XP_002127410.1 | 290 aa | 37% | 51% | |
| Drosophila melanogaster | Fruit fly | NP_610178.2 | 368 aa | 35% | 56% | |
| Apis mellifera | Honey bee | XP_392954.1 | 326 aa | 32% | 52% | |
| Strongylocentrotus purpuratus | Purple sea urchin | XP_788598.1 | 287 aa | 32% | 52% | |
| Oryza sativa | Rice | EEC81354.1 | 412 aa | 31% | 45% | |
| Nematostella vectensis | Sea anemone | XP_001628968.1 | 242 aa | 29% | 52% | |
| Populus trichocarpa | Black cottonwood | XP_002306371.1 | 443 aa | 29% | 45% | |
| Aspergillus nidulans | Fungus | XP_657927.1 | 285 aa | 27% | 44% | |
| Dictyostelium discoideum | Amoeba | XP_644630.1 | 354 aa | 27% | 44% |
Using bioinformatic analysis tools like MyHits Motif Scan[12] and various tools at ExPASy[13] and comparing to multiple sequence alignments, highly conserved potential sites of post-translational modification were identified. The following is not a comprehensive list of predicted modification sites; it includes only the ones that use highly conserved amino acids.
T216, the tyrosine for a tyrosine phosphorylation site, and S217, the serine for a predicted CK2 phosphorylation site, are completely conserved throughout the protein's evolutionary history. This suggests high likelihood that these sites are real and important for the protein's function.