Heterotrimeric G proteins are key intracellular coordinators that receive signals from cells through activation of cognate G protein-coupled receptors (GPCRs). The details of their atomic interactions and structural mechanisms have been described by many biochemical and biophysical studies. Specifically, a framework for understanding conformational changes in the receptor upon ligand binding and associated G protein activation was provided by description of the crystal structure of the β2-adrenoceptor-Gs complex in 2011. This review focused on recent findings in the conformational dynamics of G proteins and GPCRs during activation processes.
GTP-Binding Proteins* ; Heterotrimeric GTP-Binding Proteins

No abstract available.
GTP-Binding Proteins

No abstract available.
GTP-Binding Proteins*

BACKGROUNDAlthough biomedical ontologies have standardized the representation of gene products across species and databases, a method for determining the functional similarities of gene products has not yet been developed.

METHODSWe proposed a new semantic similarity measure based on Gene Ontology that considers the semantic influences from all of the ancestor terms in a graph. Our measure was compared with Resnik's measure in two applications, which were based on the association of the measure used with the gene co-expression and the protein-protein interactions.

RESULTSThe results showed a considerable association between the semantic similarity and the expression correlation and between the semantic similarity and the protein-protein interactions, and our measure performed the best overall.

CONCLUSIONThese results revealed the potential value of our newly proposed semantic similarity measure in studying the functional relevance of gene products.

Membrane Proteins/metabolism* ; Protein Binding

No Abstract Available.
GTP-Binding Proteins* ; Receptors, Cell Surface*

Background: Anemia in patients with liver cirrhosis can be due to either iron deficiency as the result of gastroesophageal bleeding or vitamin B12 and folic acid deficiency in patients with alcohol - induced liver cirrhosis. Nevertheless excessive iron level in liver can induce damages to hepatic cells and further advance the cirrhosis process. Objective: To investigate the function of iron in the treatment of anemia in liver cirrhosis patients, collecting data on plasma iron and ferritin concentrations. Subjects and method: Research on 100 patients with liver cirrhosis has been conducted at Department of Gastroenterology, Bach Mai Hospital. Results: 59% patients had low plasma iron level and 9% had high level whereas 13% and 61 % patients had low and high plasma ferritin levels respectively. Plasma iron levels reduced significantly at patients with liver cirrhosis at advanced stage (p < 0.01) and at patients with gastroesophageal (GE) haemorrhage (p < 0.05). Plasma ferritin levels reduced in patients with gastroesophageal bleeding (p < 0.05) but increased in patients with liver cirrhosis at advanced stage (p <0.01) and at alcohol - induced liver cirrhosis patients (p < 0.05). Conclusions: For patients having chronic anemia, plasma levels of iron and ferritin should be determined before a decision of prescribing iron being made.
Fibrosis ; Iron ; iron-binding seminal plasma antigen

Objective: This study seeks to determine the association between vitamin D and testosterone in healthy, adult Filipino males. Methodology: This cross-sectional study included 110 healthy, non-obese, male volunteers aged 21–40. History and physical exam were taken, and blood was drawn for vitamin D, total testosterone (TT), sex hormone binding globulin (SHBG), albumin, insulin, fasting plasma glucose, and total cholesterol. Free testosterone (FT) was calculated. Vitamin D data were classified by status and TT, FT, and SHBG levels were compared using the Kruskal–Wallis’s test. The associations of vitamin D levels with TT, FT, and SHBG were explored using multiple regression analysis. Results: Vitamin D levels were sufficient in 3 (2.7%), insufficient in 17 (15.45%), and deficient in 90 (81.8%) of the sample. There were no significant differences in the mean TT (p=0.7981), FT (p=0.8768), nor SHBG (p=0.1838) across vitamin D status. Vitamin D was not associated with TT nor FT before or after adjustment for age and age plus body mass index (BMI). Vitamin D was associated with SHBG before and after the aforementioned adjustments, but this became insignificant on sensitivity analysis. Conclusion There is no association between vitamin D and TT, FT nor SHBG in our cohort with deficient Vit D levels.
Vitamin D ; Sex Hormone-Binding Globulin

There are 13 members of the Let -7 miRNAs family which is regarded as tumor suppressor gene, locating in nine different chromosome loci. Lin28 acts as negative regulatory factor of miRNA biological recurrence. By selectively blocking the processing synthesis of the Let-7 miRNAs family, Lin28 block the inhibition effect of miRNA of proto-oncogenes and interact with RNA helicase to enhance gene translation at the same time. By not quite clear mechanism, an up-regulation of Let-7 inhibits the expression and function of Lin28. In more and more studies of human tumor, Lin28/Let-7 axsis was proved to be important significance of the tumor's occurrence and development. In this paper, we research briefly the recent progress of the molecular mechanism and related influence factors of ILin28/Let-7 axsis.
Animals ; Humans ; MicroRNAs ; RNA-Binding Proteins

No abstract available.
Binding Sites* ; Gonadotropins* ; Humans* ; Ovarian Neoplasms*