RESUMEN
Calponin is an actin filament-associated regulatory protein expressed in smooth muscle and many types ofnonmuscle cells.Three calponin isoforms 1,2,and 3 are encoded by three homologous genes CNN1,CNN2 and CNN3 in vertebrate species with cell type-specific expression and functions.Besides modulating the activity of smooth muscle myofilaments and contractility,calponin also regulates the functions of actin cytoskeleton in non-muscle cells during cell proliferation,adhesion,migration,differentiation,phagocytosis and fusion.This review focuses on the evolution,tissue and cell type-specific expression,structure-function relationships,transcriptional regulation and relevant mechanisms.
RESUMEN
Eukaryotic DNA replication is tightly restricted to only once per cell cycle in order to maintain genome stability. Cells use multiple mechanisms to control the assembly of the prereplication complex (pre-RC), a process known as replication licensing. This review focuses on the regulation of replication licensing by posttranslational modifications of the licensing factors, including phosphorylation, ubiquitylation and acetylation. These modifications are critical in establishing the pre-RC complexes as well as preventing rereplication in each cell cycle. The relationship between rereplication and diseases, including cancer and virus infection, is discussed as well.
Asunto(s)
Animales , Humanos , Acetilación , Ciclo Celular , Replicación del ADN , Genética , Fisiología , Momento de Replicación del ADN , ADN de Neoplasias , Genética , Inestabilidad Genómica , Interacciones Huésped-Patógeno , Modelos Biológicos , Neoplasias , Quimioterapia , Genética , Metabolismo , Fosforilación , Procesamiento Proteico-Postraduccional , Ubiquitinación , Virosis , Genética , MetabolismoRESUMEN
OBJECTIVE:To establish HPLC method for the determination of the principal agent in phenoxymethylpenicillin potassium tablets.METHODS:The determination was performed on Diamonsil C 18 column with column temperature at(26?1)℃.The mobile phase consisted of acetonitrile-0.02mol/L sodium acetate(70∶30)with a flow rate at1.0ml/min.The detection wavelength was set at268nm;the sensitivity was0.01AUFS and the sample size was20?l.RESULTS:Good linear correlation with peak area was noted when the detection concentration range was10.0～120.0?g/mL for phenoxymethylpeni?cillin potassium(r=0.9999,n=5).The average recovery was100.2%(RSD=0.42%).CONCLUSION:The method was rapid,simple and accurate and it can be used to determine the content of the principal agent in phenoxymethylpenicillin potas?sium tablets.
RESUMEN
Natural Killer(NK)cytotoxicity of human PML coulcb be markedly increased by human umbilical-corld-blood-derived interferon-? (P-IFN) and Astragalus membranacesu (AIMember.)but slightly inhibited by high concentration of P-IFN (105u/ml) or A-Membr. (10mg/ml) .P-IFN and A.Membr., on the other hand, could protect target cells from NK cytotoxicity.However, this effect was lower than that of their enhancement of NK cytotoxicity.Moreover, P-IFN and A.Membr .could enhance each other.NK cytotoxicity might be increased by 5 to 6 times when the both agents were com-bined ia treatment of effector cells. A.Membr could induce interferon-r which mediated the enhancing effect of A.Membr NK cytotoxicity.There was a relationship be-tween enhancing effect of P-IFN on NK activity and large molecular metabolism of effector cells. It was supposed that interferon, except for activating NK cytotoxicity directly, might stimulate lymphocytes producing other kinds of factors by which interferon might further amplify its enhancing effect on NK cytotxicity.