Morn repeat containing 1
MORN1 contains 19 different GT-AG introns, and 15 different mRNAs; 11 of which are produced by alternative splicing and 4 of which are unspliced. Of these variants there are 4 probable alternative promoters, 9 non-overlapping alternative last exons and 6 alternative polyadenylation sites. 753 bps of this gene are antisense (on + strand) to spliced SKI gene, and 193 bps to RER1 which may contribute to regulation of expression of itself or of its flanking genes.
The MORN1 gene encodes a protein of 497 amino acids and contains two overlapping conserved protein domains. The first is the MORN repeat region in which the protein contains 7 MORN repeats (at residues 38-211) belonging to protein family: pfam02493. The second is a multidomain uncharacterized protein conserved in bacteria: COG4642 which contains the MORN repeat region plus the beginning target sequence (1–211). The other 286 amino acids are less conserved among orthologs (especially distant orthologs) and belong to no known protein family.
The unmodified protein is predicted to have a molecular weight of 53,835.05 Daltons and an isoelectric point of 6.673. The protein has no long hydrophobic regions, suggesting it is not a transmembrane protein. It has been predicted to be localized in the cytoplasm, the nucleus or mitochondrial.
The genomic context may not necessarily infer function, but Morn1 has been predicted to contain a second peroxisomal targeting signal using PSORTII at residues 451: RLPPAFKHL, which may suggest interaction with PEX10 (see genomic context above).
Morn1 was predicted to have several glycosylation sites at the Serine 488 and at Threonine residues. There were also conserved Serine, Tyrosine and Threonine residues that were predicted Phosphorylation sites that were conserved among orthologs. See image of the Multiple Sequence alignment and Texshade.
The Membrane Occupation and Recognition Nexus is a repeat is found in multiple copies in several proteins including junctophilins. A MORN-repeat protein has been identified in the parasite Toxoplasma gondii and other Apicomplexan protists.
In T. gondii, MORN1 plays role in nuclear division and daughter cell budding. It is specifically associated with the spindle poles, the anterior and interior rings of the inner membrane complex during asexual reproduction/sexual reproduction; budding; and schizogony (see Apicomplexan cellular morphology).
Over-expression of MORN1 resulted in specific, severe defects in nuclear segregation and daughter cell formation. It was hypothesized that “Morn1 functions as a linker protein between certain membrane regions and the parasite's cytoskeleton.” The Morn repeats are not identical, but follow a general pattern of beginning with a YeG seqeuence, and specifically the subsequent Glycine residues are well conserved even within microbial orthologs which may suggest that the glycine residues may be important and/or involved in some structural function of the protein.
Expressed Sequence Tag and microarray data suggests that Morn1 is expressed predominantly in the brain, eyes, lungs, parathyroid, salivary gland, testis, kidneys, trachea, and to a lesser extent the ovaries, prostate, thymus and the trachea. It is expressed in adults and in fetuses. By health state, Morn1 appears to be expressed in the normal state, as well as germ cell and kidney tumors.
The orthologs of the Morn1 protein are listed below obtained by BLAST analysis. The conservation of this protein is conserved in mammals and invertebrates. Reptiles, insects and birds do not seem to show much conservation of this protein while bacteria and protists show similar conservation as in birds and reptiles, but these organisms are much more evolutionarily distant from humans.
|Organism||Accession Number||% Identity to Human Gene|
|Branchiostoma floridae (Lancelet)||XP_002590560.1||58|
|Xenopus Laevis (African clawed frog)||NP_001088789||41|
- "Entrez Gene: MORN repeat containing 1".
- Strausberg RL, Feingold EA, Grouse LH, et al. (December 2002). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. Bibcode:2002PNAS...9916899M. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
- "NCBI GenBank Record: MORN repeat containing 1". 2014-03-22.
- "National Center for Biotechnology Information AceView".
- "Conserved Domains: Conserved domains on MORN repeat-containing protein 1".
- Brendel V, Bucher P, Nourbakhsh IR, Blaisdell BE, Karlin S (March 1992). "Methods and algorithms for statistical analysis of protein sequences". Proc. Natl. Acad. Sci. U.S.A. 89 (6): 2002–6. Bibcode:1992PNAS...89.2002B. doi:10.1073/pnas.89.6.2002. PMC 48584. PMID 1549558.; "ISREC SAPS server".
- "PSORT II: Prediction of Protein Sorting Signals and Localization Sites in Amino Acid Sequences".
- la Cour T, Kiemer L, Mølgaard A, Gupta R, Skriver K, Brunak S (June 2004). "Analysis and prediction of leucine-rich nuclear export signals". Protein Eng. Des. Sel. 17 (6): 527–36. doi:10.1093/protein/gzh062. PMID 15314210.
- "ExPasy: YinOYang (Prediction of glycosylation sites in proteomes: from post-translational modifications to protein function. R Gupta.Ph.D. thesis at CBS, 2001".
- "NetPHOS: Blom, N., Gammeltoft, S., and Brunak, S. "Sequence- and structure-based prediction of eukaryotic protein phosphorylation sites." Journal of Molecular Biology: 294(5): 1351–1362, 1999".
- "CLUSTAL W: Julie D. Thompson, Desmond G. Higgins and Toby J. Gibson".
- "TeXshade version 1.4, by Eric Beitz".
- Ferguson DJ, Sahoo N, Pinches RA, Bumstead JM, Tomley FM, Gubbels MJ (April 2008). "MORN1 has a conserved role in asexual and sexual development across the apicomplexa". Eukaryotic Cell. 7 (4): 698–711. doi:10.1128/EC.00021-08. PMC 2292627. PMID 18310354.
- Gubbels MJ, Vaishnava S, Boot N, Dubremetz JF, Striepen B (June 2006). "A MORN-repeat protein is a dynamic component of the Toxoplasma gondii cell division apparatus". J. Cell Sci. 119 (Pt 11): 2236–45. doi:10.1242/jcs.02949. PMID 16684814.
- "Genecards: Expression Data Morn1".
- "NCBI BLAST".
- "PREDICTED: MORN repeat-containing protein 1 [Equus caballus] - Protein - NCBI".
- "MORN repeat-containing protein 1 isoform 1 [Mus musculus] - Protein - NCBI".
- "PREDICTED: Similar to testis specific gene A2 [Canis familiaris] - Protein - NCBI".
- "MORN repeat-containing protein 1 [Rattus norvegicus] - Protein - NCBI".
- "Hypothetical protein BRAFLDRAFT_124536 [Branchiostoma floridae] - Protein - NCBI".
- "PREDICTED: MORN repeat-containing protein 1 isoform X4 [Strongylocentr - Protein - NCBI".
- "Hypothetical protein TRIADDRAFT_27169, partial [Trichoplax adhaerens] - Protein - NCBI".
- "Predicted protein, partial [Chlamydomonas reinhardtii] - Protein - NCBI".
- "Radial spoke head component 1 L homeolog [Xenopus laevis] - Protein - NCBI".
- "Membrane occupation and recognition nexus protein MORN1 [Toxoplasma go - Protein - NCBI".
- "PREDICTED: Hypothetical protein [Taeniopygia guttata] - Protein - NCBI".
- "Radial spoke head 1 homolog [Gallus gallus] - Protein - NCBI".
- "JunctoPHilin [Caenorhabditis elegans] - Protein - NCBI".
- "NCBI: Cblast".
- Strausberg RL, Feingold EA, Grouse LH, et al. (2002). "Generation and initial analysis of more than 15,000 full-length human and mouse cDNA sequences". Proc. Natl. Acad. Sci. U.S.A. 99 (26): 16899–903. Bibcode:2002PNAS...9916899M. doi:10.1073/pnas.242603899. PMC 139241. PMID 12477932.
- Gerhard DS, Wagner L, Feingold EA, et al. (2004). "The status, quality, and expansion of the NIH full-length cDNA project: the Mammalian Gene Collection (MGC)". Genome Res. 14 (10B): 2121–7. doi:10.1101/gr.2596504. PMC 528928. PMID 15489334.
- Gregory SG, Barlow KF, McLay KE, et al. (2006). "The DNA sequence and biological annotation of human chromosome 1". Nature. 441 (7091): 315–21. Bibcode:2006Natur.441..315G. doi:10.1038/nature04727. PMID 16710414.
- Ota T, Suzuki Y, Nishikawa T, et al. (2004). "Complete sequencing and characterization of 21,243 full-length human cDNAs". Nat. Genet. 36 (1): 40–5. doi:10.1038/ng1285. PMID 14702039.