We have recently found that, , the murine leukaemia virus (MuLV)-associated protein kinase activity predominantly phosphorylates Pr65, a virus protein present in relatively small amounts in partially purified virus preparations. Other virus proteins, such as p10, Pr27 and Pr40, are also phosphorylated , but to a lesser degree. Furthermore, when immature core subparticles which are enriched in Pr65 are prepared from virions by Sepharose 6B exclusion column chromatography, about 50% of the kinase activity (as assayed with the exogenous substrate phosvitin) remains associated with the cores. We report here that this core-associated activity is distinct from Pr65 since it can be separated from Pr65 by chromatography on denatured DNA-cellulose columns followed by centrifugation of the 0·2 -NaCl-eluted fraction. Under these conditions, Pr65 is pelleted while the kinase activity, which can phosphorylate both endogenous (MuLV Pr65 and p10) as well as exogenous (phosvitin) substrates, remains in the supernatant. Interestingly, when the amount of Pr65 is reduced, as in such preparations, p10 then becomes more heavily phosphorylated.


Article metrics loading...

Loading full text...

Full text loading...


Most cited this month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error