Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.4.4 (kinesin)
 5,033 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Hepatitis C virus (HCV) is an enveloped, single-stranded RNA virus, belonging to the Flaviviridae family. HCV infection is a major cause of chronic hepatitis worldwide, leading to steatosis, liver cirrosis and hepatocellular carcinoma. Significant advances in understanding the mechanisms of HCV infection have been made since the development of a cell culture system reproducing the complete HCV cell cycle in vitro. HCV represents a new paradigm in interactions between the virus and its target cell, the human hepatocyte, due to the central role of lipoproteins in the HCV life cycle. Very low density lipoproteins are required for virus particle assembly and secretion. Upon the release, the infectious virus circulates in the blood as triglyceride-rich particles and infects cells using lipoprotein-receptor dependent mechanisms. HCV cell entry is a multi-step process: heparan sulphate and/or low-density lipoprotein receptor are cell surface factors mediating an initial virus attachment; subsequent virus interaction with tetraspanin CD81 and the human scavenger receptor SR-BI, the main HCV receptors, triggers virus movement to the tight junctions and its uptake via Claudin-1 and occludin. Another originality of HCV is that initiation of productive infection requires dynamic microtubules. Whereas other viruses use kinesin or dynein-dependent transport, HCV exploits mechanisms driven by microtubule polymerization to efficiently infect its target cell, in which virus nucleocapsid protein might play a particular role. An improved of understanding of the cellular events involved in HCV cell entry and transport, leading to the initiation of productive HCV infection, may reveal novel targets for anti-viral interventions.
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PMID:Mechanism of cell infection with hepatitis C virus (HCV)--a new paradigm in virus-cell interaction. 1982 91

Hepatitis C virus (HCV) is an enveloped RNA virus that modifies intracellular trafficking processes. The mechanisms that HCV and other viruses use to modify these events are poorly understood. In this study, we observed that two different RNA viruses, HCV and Sendai, cause inhibition of ras-related protein Rab-7 (Rab7)-dependent endosome-lysosome fusion. In both cases, viral infection causes cleavage of the Rab7 adaptor protein RILP (Rab interacting lysosomal protein), which is responsible for linking Rab7 vesicles to dynein motor complexes. RILP cleavage results in the generation of a cleaved RILP fragment (cRILP) missing the N terminus of the molecule. Although RILP localizes in a perinuclear fashion, cRILP moves to the cell periphery. Both knockdown of RILP and expression of cRILP reproduced the HCV-induced trafficking defect, and restoring full-length RILP reversed the trafficking effects of virus. For the first 3 d after electroporation of HCV RNA, intracellular virus predominates over secreted virus, but the quantity of intracellular virus then rapidly declines as secreted virus dominates. The transition from the intracellular-predominant to the secretion-predominant phenotype corresponds to the time course of cRILP generation. Expressing cRILP directly prevents intracellular virus accumulation at early times without affecting net virus production. The ability of cRILP to promote virus secretion could be prevented by a kinesin inhibitor. HCV thus modifies cellular trafficking by cleaving RILP, which serves to redirect Rab7-containing vesicles to a kinesin-dependent trafficking mode promoting virion secretion. Cleavage of a Rab adaptor protein is thus a mechanism by which viruses modify trafficking patterns of infected cells.
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PMID:Hepatitis C virus promotes virion secretion through cleavage of the Rab7 adaptor protein RILP. 2779 Oct 88