These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: A novel form of rotavirus NSP2 and phosphorylation-dependent NSP2-NSP5 interactions are associated with viroplasm assembly.
    Author: Criglar JM, Hu L, Crawford SE, Hyser JM, Broughman JR, Prasad BV, Estes MK.
    Journal: J Virol; 2014 Jan; 88(2):786-98. PubMed ID: 24198401.
    Abstract:
    Rotavirus (RV) replication occurs in cytoplasmic inclusions called viroplasms whose formation requires the interactions of RV proteins NSP2 and NSP5; however, the specific role(s) of NSP2 in viroplasm assembly remains largely unknown. To study viroplasm formation in the context of infection, we characterized two new monoclonal antibodies (MAbs) specific for NSP2. These MAbs show high-affinity binding to NSP2 and differentially recognize distinct pools of NSP2 in RV-infected cells; a previously unrecognized cytoplasmically dispersed NSP2 (dNSP2) is detected by an N-terminal binding MAb, and previously known viroplasmic NSP2 (vNSP2) is detected by a C-terminal binding MAb. Kinetic experiments in RV-infected cells demonstrate that dNSP2 is associated with NSP5 in nascent viroplasms that lack vNSP2. As viroplasms mature, dNSP2 remains in viroplasms, and the amount of diffuse cytoplasmic dNSP2 increases. vNSP2 is detected in increasing amounts later in infection in the maturing viroplasm, suggesting a conversion of dNSP2 into vNSP2. Immunoprecipitation experiments and reciprocal Western blot analysis confirm that there are two different forms of NSP2 that assemble in complexes with NSP5, VP1, VP2, and tubulin. dNSP2 associates with hypophosphorylated NSP5 and acetylated tubulin, which is correlated with stabilized microtubules, while vNSP2 associates with hyperphosphorylated NSP5. Mass spectroscopy analysis of NSP2 complexes immunoprecipitated from RV-infected cell lysates show both forms of NSP2 are phosphorylated, with a greater proportion of vNSP2 being phosphorylated compared to dNSP2. Together, these data suggest that dNSP2 interacts with viral proteins, including hypophosphorylated NSP5, to initiate viroplasm formation, while viroplasm maturation includes phosphorylation of NSP5 and vNSP2.
    [Abstract] [Full Text] [Related] [New Search]