Biology:Myticin

From HandWiki
Short description: Peptide


Myticin-prepro
Identifiers
SymbolMyticin-prepro
PfamPF10690
InterProIPR019631
OPM superfamily58
OPM protein2eem

Myticin is a cysteine-rich peptide produced in three isoforms, A, B and C, by Mytilus galloprovincialis (Mediterranean mussel), which are found primarily in marine habitats. Myticin is also produced in other species of Mytilus (Mytilus spp.), though the properties of Myticin in Mytilus galloprovincialis is understood to a greater extent.[1] Isoforms A and B show antibacterial activity against Gram-positive bacteria, while isoform C is additionally active against the fungus Fusarium oxysporum and bacterium Escherichia coli (streptomycin resistant strain D31).[2] Myticin-prepro is the precursor peptide.

The mature molecule, named myticin, consists of 40 residues, with four intramolecular disulphide bridges, an N-terminal signal peptide[3] and a cysteine array in the primary structure different from that of previously characterised cysteine-rich antimicrobial peptides. The first 20 amino acids are a putative signal peptide, and the antimicrobial peptide sequence is a 36-residue C-terminal extension. Such a structure suggests that myticins are synthesised as prepro-proteins that are then processed by various proteolytic events before storage in the hemocytes as the active peptide. Myticin precursors are expressed mainly in the haemocytes.

Role of Myticin in Mytilus galloprovincialis

AMPs (Antimicrobial peptides) play a significant role in innate immunity defenses exhibited by Bivalves. In marine organisms, AMPs are the main factor in innate immune response which helps to protect them against pathogenic microorganisms in their environment.[4] The innate immune response is thought be nonspecific, though there is limited research in this area.[5] It is unclear whether invertebrates such as bivalves have a similar immune system to vertebrates,[6] however, Myticin is expressed in the hemocytes of mussels, and recent studies have suggested that this molecule is activated after injury to its tissues.[7]

Isoform C

Isoform C is the most widely studied isoform of myticin, most likely due to its abundance and diversity. Myticin C has shown a wide diversity in Mytilus galloprovincialis, with individuals expressing unique sequences of the peptide compared to genes that were not immune related.[8] It has been shown to be an active defense mechanism against many organisms including fish rhabdovirus.[9] Isoform C has also been shown to have antiviral properties against OsHV-1,[6] which is one of the most important and devastating bivalve pathogens. Additionally, a modified version was show to have antiviral activity against HSV-1 and HSV-2 in humans, demonstrating the potential of Myticin c in human application.

References

  1. "Expression profiles of antimicrobial peptides in Mytilus coruscus" (in en). Aquaculture 548: 737709. 2022-02-15. doi:10.1016/j.aquaculture.2021.737709. ISSN 0044-8486. Bibcode2022Aquac.54837709Y. 
  2. "Myticin, a novel cysteine-rich antimicrobial peptide isolated from haemocytes and plasma of the mussel Mytilus galloprovincialis". European Journal of Biochemistry 265 (1): 71–78. October 1999. doi:10.1046/j.1432-1327.1999.00654.x. PMID 10491159. 
  3. "Molecular diversity and evolution of myticin-C antimicrobial peptide variants in the Mediterranean mussel, Mytilus galloprovincialis". Peptides 29 (7): 1094–1101. July 2008. doi:10.1016/j.peptides.2008.03.007. PMID 18440670. 
  4. "Mytilus galloprovincialis myticin C: a chemotactic molecule with antiviral activity and immunoregulatory properties". PLOS ONE 6 (8): e23140. 2011-08-08. doi:10.1371/journal.pone.0023140. PMID 21858010. Bibcode2011PLoSO...623140B. 
  5. "The Role of Anti-Viral Effector Molecules in Mollusc Hemolymph". Biomolecules 12 (3): 345. February 2022. doi:10.3390/biom12030345. PMID 35327536. 
  6. 6.0 6.1 "Antiviral Activity of Myticin C Peptide from Mussel: an Ancient Defense against Herpesviruses". Journal of Virology 90 (17): 7692–7702. September 2016. doi:10.1128/JVI.00591-16. PMID 27307570. 
  7. "Transcriptomic Analysis Reveals the Wound Healing Activity of Mussel Myticin C". Biomolecules 10 (1): 133. January 2020. doi:10.3390/biom10010133. PMID 31947557. 
  8. "Evidence of high individual diversity on myticin C in mussel (Mytilus galloprovincialis)". Developmental and Comparative Immunology 33 (2): 162–170. February 2009. doi:10.1016/j.dci.2008.08.005. PMID 18789353. 
  9. "pH-dependent solution structure and activity of a reduced form of the host-defense peptide myticin C (Myt C) from the mussel Mytilus galloprovincialis". Marine Drugs 11 (7): 2328–2346. July 2013. doi:10.3390/md11072328. PMID 23880927. 
This article incorporates text from the public domain Pfam and InterPro: IPR019631