Phosphorylated baculovirus p10 is a heat-stable microtubule-associated protein associated with process formation in Sf9 cells

Abstract

Insect ovarian Sf9 cells extend processes with complex morphologies when infected with a recombinant baculovirus encoding the catalytic subunit of protein kinase A. Within the shafts of the processes are abundant microtubules, which, in contrast to those in Sf9 cells expressing the microtubule-associated protein tau, are generally not organized into parallel bundles. During infection the late viral polypeptide p10 becomes phosphorylated by the protein kinase A catalytic subunit at its penultimate residue, Ser92. The expression or phosphorylation of other major host cell or viral polypeptides does not change, compared with polypeptides from a wild-type viral infection. Once phosphorylated, p10 associates with microtubules in the infected cells and may thereby play a role in process formation.