Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry.

The HIV-1 infectious cycle requires viral protein interactions with host factors to facilitate viral replication, packaging, and release. The infectious cycle further requires the formation of viral/host protein complexes with HIV-1 RNA to regulate the splicing and enable nucleocytoplasmic transport. The HIV-1 Rev protein accomplishes the nuclear export of HIV-1 mRNAs through multimerization with intronic cis-acting targets - the Rev response element (RRE).

Differential association of hemoglobin with proinflammatory high density lipoproteins in atherogenic/hyperlipidemic mice. A novel biomarker of atherosclerosis.

Studies in both mice and humans suggest that the anti- or proinflammatory nature of high density lipoprotein (HDL) may be a more sensitive predictor of risk for coronary heart disease events. In this study, we report the identification and characterization of two proteins (m/z 14,900 and 15,600) that are most dramatically associated with HDL in mouse models of atherosclerosis. Mass spectral analyses of proinflammatory HDL identified the two peaks to be hemoglobin (Hb) alpha and beta chains, respectively, with no apparent post-translational modification.

Proteomic analysis of in vivo-assembled pre-mRNA splicing complexes expands the catalog of participating factors.

Previous compositional studies of pre-mRNA processing complexes have been performed in vitro on synthetic pre-mRNAs containing a single intron. To provide a more comprehensive list of polypeptides associated with the pre-mRNA splicing apparatus, we have determined the composition of the bulk pre-mRNA processing machinery in living cells. We purified endogenous nuclear pre-mRNA processing complexes from human and chicken cells comprising the massive (>200S) supraspliceosomes (a.

Composition and functional characterization of the yeast spliceosomal penta-snRNP.

Pre-mRNA introns are spliced in a macromolecular machine, the spliceosome. For each round of splicing, the spliceosome assembles de novo in a series of ATP-dependent steps involving numerous changes in RNA-RNA and RNA-protein interactions. As currently understood, spliceosome assembly proceeds by addition of discrete U1, U2, and U4/U6*U5 snRNPs to a pre-mRNA substrate to form functional splicing complexes.