Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Mason-Pfizer monkey virus (M-PMV), like some other betaretroviruses, encodes a G-patch domain (GPD). This glycine-rich domain, which has been predicted to be an RNA binding module, is invariably localized at the 3' end of the pro gene upstream of the pro-pol ribosomal frameshift sequence of genomic RNAs of betaretroviruses. Following two ribosomal frameshift events and the translation of viral mRNA, the GPD is present in both Gag-Pro and Gag-Pro-Pol polyproteins. During the maturation of the Gag-Pro polyprotein, the GPD transiently remains a C-terminal part of the protease (PR), from which it is then detached by PR itself. The destiny of the Gag-Pro-Pol-encoded GPD remains to be determined. The function of the GPD in the retroviral life cycle is unknown. To elucidate the role of the GPD in the M-PMV replication cycle, alanine-scanning mutational analysis of its most highly conserved residues was performed. A series of individual mutations as well as the deletion of the entire GPD had no effect on M-PMV assembly, polyprotein processing, and RNA incorporation. However, a reduction of the reverse transcriptase (RT) activity, resulting in a drop in M-PMV infectivity, was determined for all GPD mutants. Immunoprecipitation experiments suggested that the GPD is a part of RT and participates in its function. These data indicate that the M-PMV GPD functions as a part of reverse transcriptase rather than protease.
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PMID:The G-patch domain of Mason-Pfizer monkey virus is a part of reverse transcriptase. 2217 Dec 53

Previously, we showed the association of neoadjuvant chemotherapy (NAC) response with changing the expression vector (increase or decrease) of multidrug resistance genes (MDR) in breast tumors during chemotherapy. The aim of the present study was to evaluate the relation between changes in the expression vector of MDR genes and distant metastasis-free survival. Patients (n = 120) with breast cancer (T1-4N0-3M0) treated by 2-4 cycles of NAC (CAX, FAC, and taxane regimes) and 4 cycles of adjuvant chemotherapy (FAC) were included. TaqMan-based quantitative reverse transcriptase PCR (qRT-PCR) was used to estimate the expression of the following MDR genes: ABCB1, ABCC1, ABCC2, ABCC5, ABCG1, ABCG2, GSTP1, and MVP--in biopsies before NAC and in tumor samples after chemotherapy. Comparing the corresponding expression levels allowed us to identify the vector of expression change during NAC. The results showed that 5-year distant metastasis-free survival was 73-78% in patients with a decrease in ABCB1, ABCC2, and ABCG1 expression. The up-regulation of these genes during NAC was related to a significant decrease (up to 50-55%) in metastasis-free survival (Kaplan-Meier analysis: log-rank p value = 0.006-0.03). The association of changing the expression vector of MDR genes with metastasis-free survival did not depend on tumor size, lymph node involvement, histological form, receptor status, molecular subtype, and others clinicopathological parameters of breast cancer. The obtained data suggest that changing the expression vector of MDR genes in breast tumors during NAC may be used as a new potential prognostic marker of breast cancer. An increase in tumor expression of ABCB1, ABCC2, and ABCG1 during chemotherapy is a factor of poor prognosis, whereas down-regulation of these genes--a favorable prognostic marker.
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PMID:[Correlation of metastasis-free survival in patients with breast cancer and changes in the direction of expression of multidrug resistance genes during neoadjuvant chemotherapy]. 2390 34


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