Table 2.

Characterization of hPIV common structural proteins

Localisation	Protein	Function
Associated with vRNA (nucleocapsid formation)	L	RNA-dependent RNA polymerase
	P	Phosphoprotein subunit of the RNA-dependent RNA polymerase
	N	Nucleocapsid protein
Surface glycoproteins	HN	Haemagglutinin-neuraminidase, found on the lipid envelope of hPIV and infected cells, functions in virus-host cell attachment via sialic acid receptors
	F	Fusion protein that allows the viral nucleocapsid to enter and infect a host cell; required for membrane fusion between host cells (syncytial formation)
	M	Matrix protein with a role in attaching nucleocapsids to areas of the infected cell membrane, generating the viral envelope; may be involved in viral budding