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PRINT ISSN : 2319-7692
Online ISSN : 2319-7706 Issues : 12 per year Publisher : Excellent Publishers Email : editorijcmas@gmail.com / submit@ijcmas.com Editor-in-chief: Dr.M.Prakash Index Copernicus ICV 2018: 95.39 NAAS RATING 2020: 5.38 |
Movement protein is a non-structural protein encoded by plant viruses to allow their movement from infected cell to neighbouring one. It defined as plant viruses- encoded factors that interact with plasmodesmata to mediate the intracellular spread of virus infection. viruses subvert an intracellular communication network that supports the trafficking of wide spectrum of endogenous protein and ribonucleo protein complexes that play non-cell autonomous roles in development and physiological processes. Plant viruses revealed that PD allow the cell-to-cell trafficking of virally encoded proteins, termed the movement proteins (MPs). This non-cell-autonomous protein (NCAP) pathway is similarly employed by the host to traffic macromolecules. Viral MPs bind RNA/DNA in a sequence nonspecific manner to form nucleoprotein complexes (NPC). Host proteins are then involved in the delivery of MPs and NPC to the PD orifice and help them to enter into neighbour cells. MP modify the plasmodesmata by one of two well-understood molecular mechanisms. The ER is linked to the desmotubular ER and thereby provides a direct pathway for the targeting of ER-associated VRCs to PD, mechanisms may play a role. The TGB2 and TGB3 proteins of PMTV associate with endocytic vesicles proposed to be involved in recycling TGB2 and TGB3 back to the ER once they have delivered the VRC to PD. The MP of many plant viruses form a transport tubule within the pore of the plasmodesmata that allows the transport of mature virus particles. A cell wall-associated protein that specifically binds the viral MP was purified from tobacco leaf cell walls and identified as pectin methylesterase (PME). Callose a β-1,3 glucan polymer, can be considered a regulatory component of plasmodesmata because its deposition at the plasmodesmal orifice can physically constrict the dimension of the opening, reducing the size exclusion limit (SEL), or even seal it completely, blocking plasmodesmal trafficking. Processes of cytoskeleton mediated aggregation of VRCs with host membranes and viral as well as host proteins supports the important role of the cytoskeleton as a scaffold for the anchoring and accumulation of proteins. By providing such anchored accumulation sites the cytoskeleton may support virus infection by increasing the local concentration of viral and host components required for replication, movement, and assembly, and by shielding the virus and its replication from host defense. Aggregation of proteins with support of cellular scaffolds may also facilitate cellular responses that recognize virus components and target them for storage and degradation. Viruses may have evolved means to make themselves recognizable as aggregates and thus be targeted to the microtubule-organizing centre (MTOC) to concentrate host and viral proteins in one place to facilitate replication and assembly.