Rotavirus NSP5 phosphorylation is up-regulated by interaction with NSP2 Afrikanova, Ivka and Fabbretti, Elsa and Miozzo, Maria C. and Burrone, Oscar R.,, 79, 2679-2686 (1998), doi = https://doi.org/10.1099/0022-1317-79-11-2679, publicationName = Microbiology Society, issn = 0022-1317, abstract= 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., language=, type=