Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0001175 (AIDS)
 120,706 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The major surface glycoprotein (MSG) of Pneumocystis carinii, a pathogen responsible for pulmonary infection in AIDS and other immunocompromised patients, is an abundant surface protein that potentially allows the organism to evade host defences by antigenic variation. MSG is encoded by a multicopy gene family; in two specific forms of rat-derived P. carinii, regulation of MSG expression uses a single expression site, termed the upstream conserved sequence (UCS), through two related but distinct mechanisms. In the current study, the UCS of the MSG from human-derived P. carinii was obtained using an RNA ligase-mediated rapid amplification of cDNA ends technique. Southern blot analysis demonstrated that the UCS was present in a single copy per genome, whereas multiple copies of the downstream MSG gene were present. Sequencing and restriction fragment length polymorphism analysis of polymerase chain reaction products amplified from pulmonary samples of patients with P. carinii pneumonia demonstrated that multiple MSG genes were expressed in a given host, and that different patterns of MSG expression were seen among different patients. Tandem repeats present in the single intron occurred with varying frequency in different patient isolates, potentially providing a new method for typing human isolates. Thus, human-derived P. carinii regulates MSG expression in a manner similar to P. carinii f. sp. carinii and, in immunosuppressed patients, in whom immune pressures that probably drive antigenic variation are functioning inadequately, P. carinii can express a broad repertoire of MSG variants.
 ...
PMID:Characterization of the expression site of the major surface glycoprotein of human-derived Pneumocystis carinii. 1167 77

In the course of studies on HIV-1 RNA structure, we determined that the main 5' end of viral RNA from virions and virus producer cells corresponds to G456 in the proviral DNA sequence, one or two nucleotides down-stream from the reported ends that correspond to G454 and G455. We mapped 5' ends using the highly accurate RNA ligase-mediated rapid amplification of cDNA ends (RLM-RACE) method. The reactivity of the 5' ends indicates that they are mainly capped, although the presence of some uncapped (5'-triphosphorylated) RNA cannot formally be excluded. When we used a 5' mapping method susceptible to incorporating a cytosine at the 3' end of cDNA first strands, at a position templated by the 7-methylguanosine cap, 50% of clones derived from virion RNA had incorporated the additional cytosine. Reassignment of the 5' end has consequences for the design of short RNAs used to study HIV-1 RNA structural dynamics.
AIDS Res Hum Retroviruses 2007 Aug
PMID:The major 5' end of HIV type 1 RNA corresponds to G456. 1772 22