Heterogeneous ribonucleoprotein K (hnRNP K) binds miR-122, a mature liver-specific microRNA required for hepatitis C virus replication.

Heterogeneous ribonucleoprotein K (hnRNP K) binds miR-122, a mature liver-specific microRNA required for hepatitis C virus replication. Mol Cell Proteomics. 2015 Sep 1; Authors: Fan B, Sutandy FX, Syu GD, Middleton S, Yi G, Lu KY, Chen CS, Kao CC Abstract Heterogeneous ribonucleoprotein K (hnRNP K) binds to the 5' untranslated region of the hepatitis C virus (HCV) and is required for HCV RNA replication. The hnRNP K binding site on HCV RNA overlaps with the sequence recognized by the liver-specific microRNA, miR-122. A proteome chip containing ~17,000 unique human proteins probed with miR-122 identified hnRNP K as one of the strong binding proteins. In vitro kinetic study showed hnRNP K binds miR-122 with a nanomolar dissociation constant, in which the short pyrimidine-rich residues in the central and 3' portion of the miR-122 were required for hnRNP K binding. In liver hepatocytes, miR-122 formed a co-precipitable complex with hnRNP K. High throughput Illumina DNA sequencing of the RNAs precipitated with hnRNP K was enriched for mature miR-122. SiRNA knockdown of hnRNP K in human hepatocytes reduced the levels of miR-122. These results show that hnRNP K is a cellular protein that binds and affects the accumulation of miR-122. Its ability to also bind HCV RNA near the miR-122 binding site suggests a role for miR-122 recognition of HCV RNA. PMID: 26330540 [PubMed - as supplied by publisher]
Source: Molecular and Cellular Proteomics : MCP - Category: Molecular Biology Authors: Tags: Mol Cell Proteomics Source Type: research