- STRING predicted protein interactions for human PRP36.
LOC105371752 | |||||||||||||||||||||||||||||||||||||||||||||||||||
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Identifiers | |||||||||||||||||||||||||||||||||||||||||||||||||||
Aliases | PRP36 | ||||||||||||||||||||||||||||||||||||||||||||||||||
External IDs | GeneCards: ; OMA:- orthologs | ||||||||||||||||||||||||||||||||||||||||||||||||||
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Wikidata | |||||||||||||||||||||||||||||||||||||||||||||||||||
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PRP36 (Proline Rich Protein 36) is an extracellular protein in Homo sapiens that is encoded by the PRR36 (Proline Rich Region 36) gene that contains a domain of unknown function, DUF4596, towards the C terminus of the protein. [1] The function of PRP36 is unknown, but high gene expression has been observed in various regions of the brain such as the prefrontal cortex, cerebellum, and the amygdala. [2] [3] PRP36 has one alias: Putative Uncharacterized Protein FLJ22184. [4]
The human PRR36 gene consists of 7 exons and is 5723 base pairs long. [5]
PRR36 is located on the short arm of human chromosome 19 at 19p13.2 (region 1, band 3, and sub-band 2). [5] The gene spans between base pair numbers 7868719 and 7874441 on chromosome 19 and is located between two other genes—LYPLA2P2, a pseudogene, and EVI5L, a gene which produces a protein that regulates Rab GTPase activity. [6] [7]
Alternative splicing of the PRR36 gene results in two transcript variants. PRR36 (FLJ22184) Transcript Variant 1, seen in the image below, is 4518 base pairs long and consists of six exons, of which the last five are utilized in protein coding. The protein produced, PRP36, is made up of 1346 amino acids. [8] PRR36 Transcript Variant 2 is 780 base pairs long and consists of five exons. PRR36 Transcript Variant 2 theoretically encodes a protein 260 amino acids in length. However, it is currently suspected that this variant transcript never gets translated. [5]
PRR36 Transcript Variant 1 has only been found to have only one polyadenylation site. [9]
DUF4596 on human PRP36 is 47 amino acids long, has an isoelectric point of 3.77, and is almost completely conserved across mammals. [10] Despite lacking a signal peptide, PRP36 is predicted to be excreted from the cell after it undergoes processing. [11] [12]
A few different tandem repeats, separated repeats, and repeated sequences exist throughout PRP36. These repeats are observable in primate PRP36 orthologs but are absent in PRP36 orthologs from more distantly related species such as the opossum, suggesting that some form of evolution has been occurring throughout the PRP36 sequence in relatively recent history. [10]
PRP36 is 1346 amino acids long and is proline rich, meaning that a greater proportion of proline residues exist throughout the protein, including the DUF4596 domain, in comparison with other human proteins. Proline rich proteins are often observed to be intrinsically unstructured and have been connected with protein-protein interactions in signaling pathways. [13] However, it isn't certain whether these traits hold true in PRP36. In PRP36 the amino acids isoleucine, tyrosine, and asparagine are present at a decreased proportion compared to a typical human protein. Two highly positive sequences exist towards the N terminus of PRP36 while a highly negative sequence exists within the DUF4596 domains towards the C terminus. As a whole, however, PRP36 appears to be a slightly basic and overall positively charged protein, as it has a corresponding isoelectric point of 10.98. [10] PRP36 is a polar and soluble protein. [14]
PRP36 is predicted to contain 24 phosphorylation sites in humans, including 14 serine, 9 threonine, and 1 tyrosine site. [15] [16] [17] Additionally, there are 8 predicted N-Acetylglucosamine attachment sites and 2 highly conserved predicted SUMOylation sites. [18] [19]
PRP36 secondary structure has not been explicitly determined, but predictions based on the PRR36 mRNA give some possibilities. Alpha-helixes, beta sheets, and other structure characteristics fail to be conserved across PRP36 orthologs with the exception of an alpha-helix alpha-helix beta-strand beta-strand motif that was highly conserved across mammals. [10] This motif begins slightly before and carries into the DUF4596 region, suggesting a high importance for this domain in PRP36 function.
PRP36 has medium scores for predicted interaction with two other proteins of unknown function, OVCH1 and FAM179A. [20] These predictions, however, have not been experimentally determined, so the confidence of protein-protein interaction with PRP36 isn't very high. [20]
No signal peptide or other marker is predicted to exist with the PRP36 sequence. [21] However, according to Phobius, PRP36 is predicted to be a non-cytoplasmic protein existing the extracellular space. [21] Assuming this prediction is correct, this might indicate that PRP36 undergoes unconventional protein secretion.
A single promoter is predicted to exist by Genomatix for the PRP36 protein. This promoter exists on the negative strand from position 7939226 to 7939826 and is 601 base pairs in length. [22] The PRP36 promoter region contains a number of predicted transcription factors of various types including various zinc fingers, E2F factors, and CDF factors. Of particulate note is the presence of a XGene Promoter Element on the minus strand which is a mediator of RNA polymerase II for promoters lacking a TATA box, as is the case for the PRP36 promoter. [23] The following table gives 12 transcription factors that interact with PRP36 as predicted by the ElDorado tool from Genomatix—all shown factors received a minimum Matrix Sim score of 0.877. [23]
Matrix Family | Detailed Matrix Information | Detailed Family Information | Start Position | End Position | Anchor Position | Strand | Sequence |
---|---|---|---|---|---|---|---|
O$XCPE | X gene core promoter element 1 | Activator-, mediator- and TBP-dependent core promoter element for RNA polymerase II transcription from TATA-less promoters | 513 | 523 | 518 | + | ggGCGGgaccg |
V$ZF5F | ZF5 POZ domain zinc finger, zinc finger protein 161 | ZF5 POZ domain zinc finger | 477 | 491 | 484 | + | gagcgCGCGcccccg |
V$GLIF | GLIS family zinc finger 2 | GLI zinc finger family | 16 | 32 | 24 | + | tcgaCCCCccaaccaga |
V$ZF02 | Zinc finger and BTB domain containing 7A, Pokémon | C2H2 zinc finger transcription factors 2 | 550 | 572 | 561 | + | gcagcCCCCtcccctcgcctcct |
V$E2FF | E2F transcription factor 6 | E2F-myc activator/cell cycle regulator | 490 | 506 | 498 | - | cgcggGCGGgagagccg |
V$E2FF | E2F transcription factor 2 | E2F-myc activator/cell cycle regulator | 476 | 492 | 484 | + | cgagcGCGCgcccccgg |
V$SP1F | Sp2, member of the Sp/XKLF transcription factors with three C2H2 zinc fingers in a conserved carboxyl-terminal domain | GC-Box factors SP1/GC | 189 | 205 | 197 | - | ccaggaggcgGGACcac |
V$MAZF | Myc associated zinc finger protein (MAZ) | Myc associated zinc fingers | 557 | 569 | 563 | - | aggcGAGGggagg |
V$E2FF | E2F transcription factor 2 | E2F-myc activator/cell cycle regulator | 411 | 427 | 419 | + | ccaaaGCGCgcttctcc |
O$XCPE | X gene core promoter element 1 | Activator-, mediator- and TBP-dependent core promoter element for RNA polymerase II transcription from TATA-less promoters | 493 | 503 | 498 | - | ggGCGGgagag |
V$E2FF | E2F transcription factor 3 | E2F-myc activator/cell cycle regulator | 475 | 491 | 483 | - | cggggGCGCgcgctcga |
O$XCPE | X gene core promoter element 1 | Activator-, mediator- and TBP-dependent core promoter element for RNA polymerase II transcription from TATA-less promoters | 190 | 200 | 195 | - | agGCGGgacca |
Unigene's EST cDNA Tissue Abundance display and Protein Atlas shows PRP36 as having significant expression levels in the brain, embryonic tissue, eyes, intestines, kidneys, nerves, and ovaries. [24] Additional evidence supports some of these findings, as analysis of normal tissues revealed that over 50% of the cells in the cerebellum, fetal brain, prefrontal cortex, and superior cervical ganglion expressed PRP36. [25] [26] PRP36 appears to be over-expressed in cell samples taken from patients with ductal carcinomas of the mammary gland, suggesting that the disease state and PRP36 expression might be connected. [27]
PRP36 has no known paralogs in humans, but a number of orthologs were found to exist in species throughout the mammalian kingdom. [28] PRP36 is highly conserved across primates, but a few short sequences unique to the human version of the gene do exist. [10] Based on the lack of conservation across all mammals a rapid evolution for PRP36 can be suggested. However, the DUF4596 region is highly conserved across mammals, suggesting that the domain is critical to PRP36 function while the rest of protein is more easily manipulated without leading to harm. A list of orthologs for PRP36 can be found below [28]
# | Genus and species | Common name | Divergence (MYA) [29] | Accession number | E-value | Length (aa) | Identity (%) | Similarity (%) |
---|---|---|---|---|---|---|---|---|
1 | Homo sapiens | Human | 0 | NP_001177396 | 0 | 1346 | 100 | 100 |
2 | Pan troglodytes | Chimpanzee | 6.3 | XP_009432808 | 0 | 1280 | 87 | 88 |
3 | Callithrix jacchus | Marmoset | 42.6 | XP_008985368 | 0 | 1243 | 78 | 79 |
4 | Saimiri boliviensis boliviensis | Black-capped squirrel monkey | 42.6 | XP_010347967.1 | 0 | 1161 | 75 | 77 |
5 | Otolemur garnetti | Northern greater galago | 74.0 | XP_003793753 | 5x10-158 | 1084 | 59 | 64 |
6 | Mesocricetus auratus | Golden hamster | 92.3 | XP_005085339 | 2x10-106 | 1034 | 82 | 86 |
7 | Mus musculus | House mouse | 92.3 | XP_006508977 | 6x10-104 | 1046 | 67 | 71 |
8 | Nannospalax galili | Upper Galilee Mountains blind mole-rat | 92.3 | XP_008822351.1 | 1x10-117 | 1167 | 62 | 65 |
9 | Jaculus jaculus | Lesser Egyptian jerboa | 92.3 | XP_004672230 | 1x10-123 | 1007 | 55 | 59 |
10 | Ictidomys tridecemlineatus | Thirteen-lined ground squirrel | 92.3 | XP_005332306.1 | 1x10-111 | 826 | 58 | 65 |
11 | Bubalus bubalis | Water buffalo | 94.2 | XP_006046812 | 5x10-119 | 1068 | 75 | 77 |
12 | Felis catus | House cat | 94.2 | XP_011287775 | 2x10-89 | 668 | 73 | 77 |
13 | Camelus dromedarius | Dromedary | 94.2 | XP_010976676.1 | 4x10-119 | 868 | 65 | 70 |
14 | Myotis lucifugus | Little brown bat | 94.2 | XP_006101945.1 | 4x10-111 | 935 | 58 | 63 |
15 | Balaenoptera acutorostrata scammoni | Common minke whale | 94.2 | XP_007169287.1 | 7x10-132 | 684 | 62 | 67 |
16 | Bison bison bison | American bison | 94.2 | XP_010826582 | 8x10-101 | 1054 | 51 | 58 |
17 | Vicugna pacos | Alpaca | 94.2 | XP_006206574 | 8x10-64 | 680 | 51 | 56 |
18 | Echinops telfairi | Lesser hedgehog tenrec | 98.7 | XP_004717416 | 2x10-96 | 850 | 61 | 65 |
19 | Trichechus manatus latirostris | Florida manatee | 98.7 | XP_004378653.1 | 4x10-114 | 879 | 59 | 63 |
20 | Monodelphis domestica | Gray short-tailed opossum | 162.6 | XP_007489701.1 | 4x10-85 | 653 | 48 | 54 |
Multiple sequence alignment suggests that PRP36 evolved early in mammalian lineage. [10] Mammals very distantly related to human beings, such as the opossum, have a version of the PRP36, suggesting that the protein came about prior to that evolutionary divergence. However, with exception to the DUF4596 domain, very few areas within the PRP36 sequence are conserved. [10]
At this time, the function of the PRP36 protein is not known. However, some speculation of the function can be made. In 2009, it was discovered that the source of a patient's phenotypes was a genetic condition involving a 19p13.2 microdeletion—a very small piece of chromosome was missing from the patient (the entire 19p13.2 region was not missing). [30] [31] Additional diagnoses have since been made, and a few patients have been found to have microdeltions that involve the region in which the PRR36 gene is found, meaning the PRP36 protein would not be found in these individuals. However, this region also included other genes whose functions are well known; for example the obesity observed in the patients can be traced to the deletion of the insulin receptor gene. Other symptoms, such a learning disabilities and speech impediments can be tied to similar gene deletions. [30] However, it is possible that PRP36 absence causes a minor disability that is masked by these other symptoms. Additionally, it is possible that PRP36 plays a secondary role with one or more of these other deleted genes. This second option can be slightly supported by noting that other proline rich proteins that have known function, both on human chromosome 19 and other chromosomes, tend to more frequently produce proteins that are involved in protein-protein interactions than many other general types of genes. [32]
QRICH1, also known as Glutamine-rich protein 1, is a protein that in humans is encoded by the QRICH1 gene. One notable feature of this protein is that it contains a Caspase Activation Recruitment Domain, also known as a CARD domain. As a result of having this domain, QRICH1 is believed to be involved in apoptotic, inflammatory, and host-immune response pathways.
Proline-rich 12 (PRR12) is a protein of unknown function encoded by the gene PRR12.
Protein FAM46B also known as family with sequence similarity 46 member B is a protein that in humans is encoded by the FAM46B gene. FAM46B contains one protein domain of unknown function, DUF1693. Yeast two-hybrid screening has identified three proteins that physically interact with FAM46B. These are ATX1, PEPP2 and DAZAP2.
ARMH3 or Armadillo Like Helical Domain Containing 3, also known as UPF0668 and c10orf76, is a protein that in humans is encoded by the ARMH3 gene. Its function is not currently known, but experimental evidence has suggested that it may be involved in transcriptional regulation. The protein contains a conserved proline-rich motif, suggesting that it may participate in protein-protein interactions via an SH3-binding domain, although no such interactions have been experimentally verified. The well-conserved gene appears to have emerged in Fungi approximately 1.2 billion years ago. The locus is alternatively spliced and predicted to yield five protein variants, three of which contain a protein domain of unknown function, DUF1741.
TM6SF2 is the Transmembrane 6 superfamily 2 human gene which codes for a protein by the same name. This gene is otherwise called KIAA1926. Its exact function is currently unknown.
DEP Domain Containing Protein 1B also known as XTP1, XTP8, HBV XAg-Transactivated Protein 8, [formerly referred to as BRCC3] is a human protein encoded by a gene of similar name located on chromosome 5.
Proline-rich protein 21 (PRR21) is a protein of the family of proline-rich proteins. It is encoded by the PRR21 gene, which is found on human chromosome 2, band 2q37.3. The gene exists in several species, both vertebrates and invertebrates, including humans. However, the protein have few conserved regions among species.
Transmembrane protein 251, also known as C14orf109 or UPF0694, is a protein that in humans is encoded by the TMEM251 gene. One notable feature of this protein is the presence of proline residues on one of its predicted transmembrane domains., which is a determinant of the intramitochondrial sorting of inner membrane proteins.
Leucine-Rich Single-Pass Membrane Protein 1 (LSMEM1) is a protein that, in humans, is encoded by the LSMEM1 gene.
C3orf70 also known as Chromosome 3 Open Reading Frame 70, is a 250aa protein in humans that is encoded by the C3orf70 gene. The protein encoded is predicted to be a nuclear protein; however, its exact function is currently unknown. C3orf70 can be identified with known aliases: Chromosome 3 Open Reading Frame 70, AK091454, UPF0524, and LOC285382.
TMEM249 is a protein that in humans is encoded by the C8orfk29 gene.
LOC105377021 is a protein which in humans is encoded by the LOC105377021 gene. LOC105377021 exhibits expressional pathology related to breast cancer, specifically triple negative breast cancer. LOC105377021 contains a serine rich region in addition to predicted alpha helix motifs.
PRR29 is a protein encoded by the PRR29 gene located in humans on chromosome 17 at 17q23.
Glutamate Rich Protein 2 is a protein in humans encoded by the gene ERICH2. This protein is expressed heavily in male tissues specifically in the testes, and proteins are specifically found in the nucleoli fibrillar center and the vesicles of these testicular cells. The protein has multiple protein interactions which indicate that it may play a role in histone modification and proper histone functioning.
Proline-rich protein 30 is a protein in humans that is encoded for by the PRR30 gene. PRR30 is a member in the family of Proline-rich proteins characterized by their intrinsic lack of structure. Copy number variations in the PRR30 gene have been associated with an increased risk for neurofibromatosis.
UPF0575 protein C19orf67 is a protein which in humans is encoded by the C19orf67 gene. Orthologs of C19orf67 are found in many mammals, some reptiles, and most jawed fish. The protein is expressed at low levels throughout the body with the exception of the testis and breast tissue. Where it is expressed, the protein is predicted to be localized in the nucleus to carry out a function. The highly conserved and slowly evolving DUFF3314 region is predicted to form numerous alpha helices and may be vital to the function of the protein.
Chromosome 21 Open Reading Frame 58 (C21orf58) is a protein that in humans is encoded by the C21orf58 gene.
Transmembrane protein 171 (TMEM171) is a protein that in humans is encoded by the TMEM171 gene.
Family with Sequence Similarity 155 Member B is a protein in humans that is encoded by the FAM155B gene. It belongs to a family of proteins whose function is not yet well understood by the scientific community. It is a transmembrane protein that is highly expressed in the heart, thyroid, and brain.
TMEM275 is a protein that in humans is encoded by the TMEM275 gene. TMEM275 has two, highly-conserved, helical trans-membrane regions. It is predicted to reside within the plasma membrane or the endoplasmic reticulum's membrane.