Disease relevance of MYOM2

• In addition, M protein/fibrinogen complexes were identified in tissue biopsies from a patient with necrotizing fasciitis and STSS, further underlining the pathogenic significance of such complexes in severe streptococcal infections [1].
• Inhibition of complement-mediated opsonization and phagocytosis of Streptococcus pyogenes by D fragments of fibrinogen and fibrin bound to cell surface M protein [2].
• Identification of the primary structures containing tissue-crossreactive as opposed to protective epitopes should not only allow the development of safe and effective M protein vaccines, but may also provide insights into the pathogenesis of rheumatic heart disease [3].
• These results reveal that the molecule produced in the E. coli and transported into the periplasm may be the complete M protein as it exists on the streptococcus [4].
• The results support the view that the hyaluronidases associated with the temperate bacteriophages from various M types of group A streptococci do not share common antigenic determinants but that an immunological specificity exists that parallels the serologic specificity of the M protein of the host strains [5].

Psychiatry related information on MYOM2

• The Id determinants of M protein was detected on the cell surface and in the cytoplasm of pathologic cells in the peripheral blood [6].

High impact information on MYOM2

• M protein, a classical bacterial virulence determinant, forms complexes with fibrinogen that induce vascular leakage [1].
• Here we find that M protein, released from the streptococcal surface, forms complexes with fibrinogen, which by binding to beta2 integrins of neutrophils, activate these cells [1].
• In mice, injection of M protein or subcutaneous infection with S. pyogenes causes severe pulmonary damage characterized by leakage of plasma and blood cells [1].
• The M protein is the antigen on the surface of group A streptococci that allows these bacteria to resist phagocytosis [7].
• DNA's from two spontaneous, independent M- variants contained small (approximately 50 base pairs) deletions which were mapped to identical restriction fragments within or adjacent to the M protein coding sequence [7].

Chemical compound and disease context of MYOM2

• Molecular analysis of the role of the group A streptococcal cysteine protease, hyaluronic acid capsule, and M protein in a murine model of human invasive soft-tissue infection [8].
• We conclude that the group A streptococcal hyaluronic acid capsule and M protein, but not the cysteine protease, are critical for the development of tissue necrosis, secondary bacteremia, and lethal infection in a murine model of human necrotizing fasciitis [8].
• The average relative dose intensity (DI) of conventional oral melphalan and prednisone therapy received by 93 newly diagnosed multiple myeloma patients was correlated with survival and with percent reduction in M-protein [9].
• Each of the peptides, designated S-CB7-(23-35)-Cys, S-CB7-(18-35), and S-CB7-(13-35), when conjugated to lysylated tetanus toxoid with glutaraldehyde, was capable of stimulating formation of protective anti-type 24 M protein antibodies in rabbits [10].
• The M protein of mouse hepatitis virus (MHV) is a triple-spanning membrane glycoprotein that is exclusively O-glycosylated [11].

Biological context of MYOM2

• We identified two immunoglobin domains (Mp2-Mp3) of M-protein as a site binding to the central region of light meromyosin [12].
• Transient transfection studies of cultured cells revealed that the myosin-binding site seems involved in the targeting of M-protein to its location in the myofibril [12].
• Expression of sarcomeric myosin heavy chain (sMyHC) is observed in a small minority of cells, while other sarcomeric proteins, such as nebulin, myosin binding protein C (MyBP-C), myomesin and M-protein are not expressed at all [13].
• The antibodies directed against the amino acid sequence Ile-Arg-Leu-Arg of the nephritogenic type 1 M protein reacted in a fibrillar pattern with mesangial cells cultured from isolated glomeruli [14].
• Streptococcal M protein extracted by nonionic detergent. II. Analysis of the antibody response to the multiple antigenic determinants of the M-protein molecule [15].

Anatomical context of MYOM2

• The Mr 165,000 M-protein myomesin: a specific protein of cross-striated muscle cells [16].
• Similarly, myomesin and M-protein were only perceptible in striated myofibrils [17].
• Furthermore, the relative number of M-protein negative myotubes varied in cultures derived from different muscles [17].
• Assembly of titin, myomesin and M-protein into the sarcomeric M band in differentiating human skeletal muscle cells in vitro [17].
• A detailed molecular map describing the arrangement of titin, M-protein and myomesin in this part of the sarcomere was recently proposed [17].

Associations of MYOM2 with chemical compounds

• Muscle-type creatine kinase interacts with central domains of the M-band proteins myomesin and M-protein [18].
• Intron positions and phases are essentially identical to those identified in M-protein [19].
• An NH2-terminal peptide of type 24 M protein was chemically synthesized and then extended to include NH2-terminal peptides of types 6 and 5 M proteins yielding a 34-residue hybrid peptide containing a cysteine residue at its COOH-terminus [20].
• Protective and heart-crossreactive epitopes located within the NH2 terminus of type 19 streptococcal M protein [21].
• These results are consistent with our previous studies which suggested that fatty acids ester linked with glycerol teichoic acid rather than M protein of streptococci binds the organisms to epithelial cells [22].

Physical interactions of MYOM2

• Here we show that streptococcal M protein interacts with TLR2 on human peripheral blood monocytes [23].
• The surface M protein of GAS binds CD46 and mediates GAS adherence to keratinocytes [24].
• VSV M protein binds the mRNA export factor Rae1 that is in complex with Nup98, resulting in nuclear retention of mRNAs [25].
• M protein of a Streptococcus dysgalactiae human wound isolate shows multiple binding to different plasma proteins and shares epitopes with keratin and human cartilage [26].
• Morphologically, these beta 2m-binding bacteria exhibited M protein-like projections in contrast to the smooth surfaces of unlabeled cells [27].

Regulatory relationships of MYOM2

• Western blot analysis revealed that VSV M-protein did not inhibit the nuclear translocation of activated STAT3 but did inhibit its tyrosine phosphorylation [28].
• These results show that the M protein inhibits transcription from cellular as well as viral promoters and that the M protein does not regulate the IFN promoter any differently from viral promoters [29].
• Invasion assays with Lactococcus lactis that express M protein demonstrated the dependence of CD46-promoted invasion on interaction with M protein [24].
• Supernatants derived from T cells stimulated with M proteins or M protein-expressing bacteria suppressed bystander T cell proliferation through IL-10 secretion [30].
• In addition, activation of CD46 through streptococcal M protein induced the expression of granzyme B, providing a second means for these cells to regulate an immune response [30].

Other interactions of MYOM2

• At pH 6.8, the dissociation constants for the myomesin/MM-CK and the M-protein/MM-CK binding were in the range of 50-100 nM and around 1 microM, respectively [18].
• An interaction was observed with domains six to eight of the closely related M-protein but not with several other Ig-like domains, including an M-band domain, of titin [18].
• Identification of the streptococcal M protein binding site on membrane cofactor protein (CD46) [31].
• Inhibition of STAT activation was not dependent on tyrosine 759 of the IL-6 signal transducer gp130, suggesting that the inhibitory action of VSV M-protein is not mediated by the induction of the suppressor of cytokine signaling 3 [28].
• These findings suggest that the PSAP motif of M protein is not critical for budding and that there are fundamental differences between PTAP-containing viruses (Ebola virus and human immunodeficiency virus type 1) and PPPY-containing viruses (VSV and rabies virus) regarding their dependence on specific host factors for efficient budding [32].

Analytical, diagnostic and therapeutic context of MYOM2

• Immunofluorescent microscopy and ELISA demonstrate the presence of M protein on its surface [33].
• Immunofluorescence inhibition tests, using purified M proteins as soluble inhibitors of heart-cross-reactive antibodies, revealed the number and M protein serotype distribution of the tissue-cross-reactive epitopes [34].
• A resurgence of invasive streptococcal diseases and rheumatic fever has appeared in outbreaks over the past 10 years, with a predominant M1 serotype as well as others identified with the outbreaks. emm (M protein) gene sequencing has changed serotyping, and new virulence genes and new virulence regulatory networks have been defined [35].
• None of the antisera reacted with heterologous serotypes of M protein and none reacted with frozen sections of human heart tissue [10].
• The dissection of protective and pathogenic epitopes of streptococcal M protein is an important step in allowing the development of a safe anti-streptococcal synthetic vaccine [36].

References