Identification of heat shock protein 70 in the rabies virion.

We investigated a 73-kDa polypeptide (p73), a minor component of the rabies virion (HEP-Flury and ERA strains), accounting for as much as 1% of total virion proteins. Two-dimensional gel electrophoresis and immunoblotting with the antiserum against the heat shock protein 70 (hsp70) demonstrated that p73 was identical to a constitutive type of cellular hsp70. The antiserum also detected p73/hsp70 in the purified virions of other negative-stranded RNA viruses, such as vesicular stomatitis virus (New Jersey serotype), Newcastle disease virus (Miyadera strain), and influenza A virus (PR8 strain), among which, however, the contents were variable.