Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.2.1.23 (beta-galactosidase)
 14,648 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We have tested the functional compatibility between rev protein of human immunodeficiency virus type I (HIV-I) and rex protein of human T-cell lymphotropic virus type I (HTLV-I). Each protein recognized the other's cis-acting sequence, albeit at reduced levels. Both proteins localize predominantly in the nucleolus. We have identified a new nucleolar-targeting signal in rev protein, which was homologous to that of rex protein. The sequence [35-RQARRNRRRRWRERQR-50] in rev protein, when fused to the amino-terminus of beta-galactosidase, directed the hybrid protein to the cell nucleolus. A deletion mutant which lacks several amino acid residues within the signal failed to function in the CAT assay system. These results demonstrate that the nucleolar targeting signals are essential for the functions of Rev and Rex.
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PMID:Functional similarity of HIV-I rev and HTLV-I rex proteins: identification of a new nucleolar-targeting signal in rev protein. 278 17

Stem cells of fetal origin lie between embryonic and adult stem cells in terms of potentiality. Because of the ethical controversy surrounding embryonic stem cells and the relatively inferior quality of adult stem cells, the use of fetal stem cells would be an attractive option in future therapeutic applications. Here, we have investigated primitive characteristics of human umbilical-cord-derived fetal mesenchymal stem cells (UC fMSCs) during extensive expansion. We have successfully isolated and cultured UC fMSCs from all UC samples, but with two early fungal contaminations. UC fMSCs proliferated without significant evidence of morphological changes, and the average cumulative population-doubling level was over 25 for about 3 months. UC fMSCs showed the positive expression of several CD markers, known to be related to MSCs, including CD73 (SH-3, 4), CD90 (Thy-1), CD105 (SH-2), CD117 (c-kit), and CD166 (ALCAM). They demonstrated primitive properties throughout the expansion period: multilineage differentiation potentials examined by functional assays, a variety of pluripotent stem cell markers including Nanog, Oct-4, Sox-2, Rex-1, SSEA-3, SSEA-4, Tra-1-60, and Tra-1-81, minimal evidence of senescence as shown by beta-galactosidase staining, and the consistent expression of telomerase activity. These results suggest that UC fMSCs have more primitive properties than adult MSCs, which might make them a useful source of MSCs for clinical applications.
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PMID:Fetal mesenchymal stem cells derived from human umbilical cord sustain primitive characteristics during extensive expansion. 1894 82