Indeed, another transcription-splicing coupling factor, TCERG1 directly through multiple interactions with FF domains in the former. Insight into the role of Diperodon Tat-SF1 in the HIV-1 lifecycle has previously been limited to immunodepletions and in vitro analyses or transient overexpression experiments. In this manuscript, we present studies that Orbifloxacin utilize RNA interference to reevaluate Tat-SF1��s role in Tat transactivation and HIV-1 replication in vivo. We found that Tat-SF1 depletion did not affect transcription from the HIV-1 LTR and did not alter the overall level of viral transcripts; however, Tat-SF1 depletion resulted in a significant decrease in viral replication. This study demonstrates that the major effect upon knockdown of Tat-SF1 was a change in the ratio of unspliced to fully spliced HIV-1 RNAs. Based on our data, we propose a novel activity for Tat-SF1 as a post-transcriptional regulator of viral pre-mRNAs. Abnormal aggregation of polypeptides into amyloid-like fibrils is associated with more than 20 known human disorders collectively referred to as protein misfolding or conformational diseases. Despite little shared sequence homology, amyloid-forming polypeptides show a common propensity to misfold into highlyordered polymers that are rich in fibrillar b-sheet structure. Distinct amyloidogenic polypeptides are genetically implicated in the progression of human neurodegenerative disorders, including Alzheimer��s, Parkinson��s, polyglutamine, and prion diseases. Human polyglutamine disorders such as Machado-Joseph disease and Huntington��s disease are caused by aberrant codon expansion of CAG trinucleotide tracts within unrelated genes encoding polyglutamine-domain proteins. In HD, expansions beyond 37 consecutive glutamines within the huntingtin protein confer a toxic gain-of-function phenotype related to its intracellular aggregation in neurons. Proteinaceous huntingtin aggregates are diagnostic hallmarks of HD neuropathology and coincide with neurological symptoms in humans as well as in transgenic models of the disease. These intracellular aggregates are composed chiefly of polyglutamine-containing amino-terminal fragments of huntingtin that arise by proteolysis. Consequently, the first exon of the human Huntingtin gene containing an expanded CAG repeat is sufficient to induce HDlike pathology, including intracellular aggregates and neurodegeneration, in transgenic mice models.