Glycoproteins M and N of human herpesvirus 8 form a complex and inhibit cell fusion.
Glycoproteins M (gM) and N (gN) are well conserved across the herpesvirus family and their involvement in virus penetration and egress is well described, especially for alphaherpesviruses. Because there was no previous study on the homologues of human herpesvirus 8 glycoproteins M (gM8) and N (gN8), we analysed their biochemical and functional characteristics. We found that: (i) gM8 aggregated following heat treatment; (ii) gM8 was a virion component; (iii) gM8 and gN8 were N-glycosylated; (iv) gM8 formed a specific complex with gN8; and (v) gN8 was required for functional processing of gM8. Co-expression of gM8 and gN8 inhibited cell fusion induced either by a combination of herpes simplex virus type 1 glycoproteins or by Molony murine leukaemia virus envelope protein. These results indicate that, in addition to the similar biochemical properties, the fusion inhibition reported previously only for alphaherpesviruses is a function conserved in the gammaherpesvirus subfamily.
Koyano
Shin
S
Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Mailstop G18, Herpesvirus Section, 1600 Clifton Road, Atlanta, GA 30333, USA.
Mar
Eng-Chun
EC
Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Mailstop G18, Herpesvirus Section, 1600 Clifton Road, Atlanta, GA 30333, USA.
Stamey
Felicia R
FR
Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Mailstop G18, Herpesvirus Section, 1600 Clifton Road, Atlanta, GA 30333, USA.
Inoue
Naoki
N
Division of Viral and Rickettsial Diseases, Centers for Disease Control and Prevention, Mailstop G18, Herpesvirus Section, 1600 Clifton Road, Atlanta, GA 30333, USA.
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002459:Cell Fusion; D002460:Cell Line; D004279:DNA, Viral / Q000235:genetics; D005814:Genes, Viral; D006023:Glycoproteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology; D018259:Herpesvirus 1, Human / Q000235:genetics / Q000502:physiology; D019288:Herpesvirus 8, Human / Q000235:genetics / Q000472:pathogenicity / Q000502:physiology*; D006801:Humans; D046911:Macromolecular Substances; D051379:Mice; D008979:Moloney murine leukemia virus / Q000235:genetics / Q000502:physiology; D013045:Species Specificity; D014162:Transfection; D014407:Tumor Cells, Cultured; D014764:Viral Proteins / Q000737:chemistry / Q000235:genetics / Q000502:physiology*
D004279:DNA, Viral; D006023:Glycoproteins; D046911:Macromolecular Substances; D014764:Viral Proteins