RT Journal Article SR Electronic(1) A1 Afrikanova, Ivka A1 Fabbretti, Elsa A1 Miozzo, Maria C. A1 Burrone, Oscar R.YR 1998 T1 Rotavirus NSP5 phosphorylation is up-regulated by interaction with NSP2 JF Journal of General Virology, VO 79 IS 11 SP 2679 OP 2686 DO https://doi.org/10.1099/0022-1317-79-11-2679 PB Microbiology Society, SN 1465-2099, AB We have previously shown that a number of isoforms of the non-structural rotavirus protein NSP5 are found in virus-infected cells. These isoforms differ in their level of phosphorylation which, at least in part, appears to occur through autophosphorylation. NSP5 co-localizes with another non-structural protein, NSP2, in the viroplasms of infected cells where virus replication takes place. We now show that NSP5 can be chemically cross-linked in living cells with the viral polymerase VP1 and NSP2. Interaction of NSP5 with NSP2 was also demonstrated by co- immunoprecipitation of NSP2 and NSP5 from extracts of UV-treated rotavirus-infected cells. In addition, in transient transfection assays, NSP5 phosphorylation in vivo was enhanced by coexpression of NSP2. An NSP5 C-terminal domain deletion mutant, was completely unable to be phosphorylated either in the presence or absence of NSP2. However, a 33 aa N-terminal deletion mutant of NSP5 was shown to become hyperphosphoryl- ated in vivo and to be insensitive to NSP2 activation, suggesting a regulatory role for this domain in NSP5 phosphorylation and making it a candidate for the interaction with NSP2. These mutants also allow a preliminary mapping of NSP5 autophosphorylation activity., UL https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-79-11-2679