Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0021051 (immunodeficiency)
 71,517 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This article describes a method for selecting single-stranded DNA (ssDNA) molecules that bind with high-affinity aptamers to specific target proteins. This SELEX (systematic evolution of ligands by exponential enrichment) method is similar to other "primer-free" approaches where the random sequence ssDNA starting pool has no fixed sequences at the 5' and 3' termini. Therefore, there are no predetermined sequences that could bias selection. Like other SELEX methods, repeated cycles (typically 5-15) of selection and then amplification and reselection are used. The method differs from other primer-free approaches in that the key step for regenerating new material for subsequent rounds is ligation of the selected ssDNA to a defined sequence oligonucleotide using thermostable RNA ligase. Under specific conditions, this ligase ligated 30-nt random sequence ssDNA (5'-N(30)-3') to a specified 20-nt ssDNA with approximately 50% efficiency. Efficiency was improved to approximately 90% by the addition of a single T residue to the 3' end (5'-N(29)T-3'). High efficiency in this step is critical, especially early in the procedure because any selected material that is not ligated is lost. In this study, human immunodeficiency virus reverse transcriptase was used as the target protein, but the method could be applied to essentially any protein.
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PMID:A primer-free method that selects high-affinity single-stranded DNA aptamers using thermostable RNA ligase. 2142 Sep 26

PSIP1 (PC4 and SFRS1 interacting protein 1) encodes two splice variants: lens epithelium-derived growth factor or p75 (LEDGF/p75) and p52. PSIP1 gene products were shown to be involved in transcriptional regulation, affecting a plethora of cellular processes, including cell proliferation, cell survival, and stress response. Furthermore, LEDGF/p75 has implications for various diseases and infections, including autoimmunity, leukemia, embryo development, psoriasis, and human immunodeficiency virus integration. Here, we reported the first characterization of the PSIP1 promoter. Using 5' RNA ligase-mediated rapid amplification of cDNA ends, we identified novel transcription start sites in different cell types. Using a luciferase reporter system, we identified regulatory elements controlling the expression of LEDGF/p75 and p52. These include (i) minimal promoters (-112/+59 and +609/+781) that drive the basal expression of LEDGF/p75 and of the shorter splice variant p52, respectively; (ii) a sequence (+319/+397) that may control the ratio of LEDGF/p75 expression to p52 expression; and (iii) a strong enhancer (-320/-207) implicated in the modulation of LEDGF/p75 transcriptional activity. Computational, biochemical, and genetic approaches enabled us to identify the transcription factor Sp1 as a key modulator of the PSIP1 promoter, controlling LEDGF/p75 transcription through two binding sites at -72/-64 and -46/-36. Overall, our results provide initial data concerning LEDGF/p75 promoter regulation, giving new insights to further understand its biological function and opening the door for new therapeutic strategies in which LEDGF/p75 is involved.
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PMID:LEDGF/p75 TATA-less promoter is driven by the transcription factor Sp1. 2201 92