Hepatocyte nuclear factors (HNFs) are a heterogeneous class of evolutionarily conserved transcription that required for cellular differentiation and metabolism. Mutations in HNF-1α HNF-4α genes impair insulin secretion cause type 2 diabetes. Regulation HNF-4/HNF-1 expression by HNF-3α HNF-3β was studied embryoid bodies which one or both alleles were inactivated. positively regulated the HNF-4α/HNF-1α their downstream targets, implicating role also necessary . In contrast, acts as negative...

Hepatocyte nuclear factors 3 (HNF-3) belong to an evolutionarily conserved family of transcription that are critical for diverse biological processes such as development, differentiation, and metabolism. To study the physiological role HNF-3α, we generated mice lack HNF-3α by homologous recombination in embryonic stem cells. Mice homozygous a null mutation gene develop complex phenotype is characterized abnormal feeding behavior, progressive starvation, persistent hypoglycemia,...

A key step in autophagy is the conjugation by E3-like Atg12-Atg5-Atg16 complex of ubiquitin-like protein Atg8 to phosphatidylethanolamine on autophagosomal membrane, a process known as lipidation. Previous work yeast showed that recruitment preautophagosomal structure mediated interaction Atg16 with phosphatidylinositol 3-phosphate-binding Atg21, and association Atg12 scaffold Atg1 kinase complex, Atg17. Here, we conducted reverse two-hybrid screen identify residues Atg17 critical for...

The systems which control the levels of gluconeogenic enzymes in Saccharomyces cerevisiae have been bypassed to ascertain their physiological significance. coding regions genes FBP1 and PCK1, encode fructose-1,6-bisphosphatase phosphoenolpyruvate carboxykinase, put under promoter ADC1 (alcohol dehydrogenase I), a gene not repressed by glucose, introduced into yeast multicopy plasmids. transformed cells show high during growth on glucose. Generation time yield expressing either or...

Type 2 Maturity Onset Diabetes of the Young (MODY2) is a monogenic autosomal disease characterized by primary defect in insulin secretion and hyperglycemia. It results from GCK gene mutations that impair enzyme activity. Between 2006 2010, we investigated 66 diabetic children southern Italy with suspected MODY2. Denaturing High Performance Liquid Chromatography (DHPLC) sequence analysis revealed 19 28 children, six which were novel: p.Glu40Asp, p.Val154Leu, p.Arg447Glyfs, p.Lys458_Cys461del,...

Glucokinase acts as the pancreatic glucose sensor and plays a critical role in regulation of insulin secretion by β-cell. Heterozygous mutations glucokinase-encoding GCK gene, which result reduction enzymatic activity, cause monogenic form diabetes, MODY2 (maturity-onset diabetes young 2). We have identified functionally characterized missense gene diabetic families that protein Leu165→Phe, Glu265→Lys Thr206→Met. The first two are novel co-segregate with phenotype their respective not found...

Genetic studies have shown that mutations in the gene encoding hepatocyte nuclear factor (HNF)-4alpha, a member of steroid/thyroid hormone receptor superfamily, give rise to early-onset type 2 diabetes (MODY1). The functional properties mutant HNF-4alpha proteins and molecular mechanisms by which they impair insulin secretion are largely unknown. In present study, we investigated transcriptional activation, DNA binding properties, protein dimerization activity three missense...

Hepatocyte nuclear factor 1-α (HNF-1α) is a homeodomain transcription expressed in variety of tissues (including liver and pancreas) that regulates wide range genes. Heterozygous mutations the gene encoding HNF-1α (HNF1A) cause familial young-onset diabetes, also known as maturity-onset diabetes young, type 3 (MODY3). The variability MODY3 clinical phenotype can be due to environmental genetic factors well position mutations. Thus, functional characterization HNF1A might provide insight into...

Glucokinase (GK) acts as a glucose sensor in the pancreatic beta-cell and regulates insulin secretion. Heterozygous mutations human GK-encoding GCK gene that reduce activity index increase glucose-stimulated secretion threshold cause familial, mild fasting hyperglycaemia, also known Maturity Onset Diabetes of Young type 2 (MODY2). Here we describe biochemical characterization five missense GK mutations: p.Ile130Thr, p.Asp205His, p.Gly223Ser, p.His416Arg p.Ala449Thr. The enzymatic analysis...

PROPPINs are phosphoinositide-binding β-propeller proteins that mediate membrane recruitment of other and involved in different remodeling processes. The main role is their function autophagy, where they act at steps phagophore formation. human PROPPIN WIPI4 (WDR45) forms a complex with ATG2 elongation, mutations this gene cause protein-associated neurodegeneration (BPAN). yeast functional counterpart Atg18, although its closest sequence homolog another member the family, Hsv2, whose remains...

Summary Background Mutations in the GCK gene lead to different forms of glucokinase ( )‐disease, activating mutations cause hyperinsulinaemic hypoglycaemia while inactivating monogenic diabetes. Hyperinsulinism HI ) is a heterogeneous condition with significant genetic component. The major causes are channelopathies, other rare and being caused by genes such as . Objective To describe clinical presentation four families mutations, explore pathogenicity novel mutation identified through...

The question of how the loss regulatory mechanisms for a metabolic enzyme would affect fitness corresponding organism has been addressed. For this, fructose-1,6-bisphosphatase (FbPase) from Saccharomyces cerevisiae taken as model. Yeast strains in which different controls on FbPase (catabolite repression and inactivation; inhibition by fructose-2,6-bisphosphate AMP) have removed constructed. These express during growth glucose either native yeast FbPase, Escherichia coli is insensitive to...

In an attempt to study the role of glucokinase (GK) and effects glucose peptides on GK gene expression activity this enzyme in hypothalamus, we used two kinds biological models: hypothalamic GT1-7 cells rat slices. The was reduced by insulin (INS) not modified different concentrations, while activities were significantly peptides. Interestingly, a distinctive pattern between ventromedial hypothalamus (VMH) lateral (LH) found, with higher VMH as concentrations rose, LH decreased at 2.8 20 mM...

Hepatocyte nuclear factors 3 (HNF-3α, -3β and -3γ) belong to an evolutionarily conserved family of transcription that are critical for diverse biological processes such as development, differentiation metabolism. Gene expression studies have shown HNF3 proteins regulators the early-onset type 2 diabetes genes HNF-1α, HNF-4α IPF-1/PDX-1 (MODY3, 1 4, respectively) glucagon pancreatic α-cell function. In this study, we investigated whether genetic variation in encoding HNF-3α, HNF-3β HNF-3γ...

Abstract VPS13A is a lipid transfer protein localized at different membrane contact sites between organelles, and mutations in the corresponding gene produce rare neurodegenerative disease called chorea‐acanthocytosis (ChAc). Previous studies showed that depletion HeLa cells results an accumulation of endosomal lysosomal markers, suggesting defect degradation capacity leading to partial autophagic dysfunction. Our goal was determine whether compounds modulate endo‐lysosomal pathway could be...

PROPPINs/WIPIs are β-propeller proteins that bind phosphoinositides and contribute to the recruitment of protein complexes involved in membrane remodelling processes such as autophagosome formation endosomal trafficking. Yeast Atg21 mammalian WIPI2 interact with Atg16/ATG16L1 mediate lipidation machinery autophagosomal membrane. Here, we used reverse double two-hybrid method (RD2H) identify residues Atg16 critical for protein-protein binding. Although our results generally consistent crystal...

Fructose-1,6-bisphosphatase (FruP2ase) from Saccharomyces cerevisiae is rapidly inactivated upon addition of glucose to a culture growing on non-sugar carbon sources. Under the same conditions FruP2ases Schizosaccharomyces pombe or Escherichia coli expressed in S. were not affected. A chimaeric protein containing first 178 amino acids N-terminal half FruP2ase fused E. beta-galactosidase was susceptible catabolite inactivation. Elimination putative destruction box, RAELVNLVG ... KK .... K.,...

Hypoglycaemic drugs that close the KATP channel have been tested in patients with permanent neonatal diabetes due to glucokinase mutations (PNDM-GCK). From results obtained, it has suggested this treatment may be beneficial carrying GCK mild kinetic defects. The aim of study was evaluate analysis activity as a predictive factor for response sulphonylureas PNDM-GCK.The clinical characteristics two siblings PNDM born non-consanguineous parents are described. Mutation KCNJ11, INS and genes done...

Abstract The reverse two-hybrid system is a powerful method to select mutations that disrupt the interaction between two proteins and therefore identify residues involved in this interaction. However, usefulness of technique has been limited by its relative complexity when compared classical system, since an additional selection step required eliminate high background uninformative truncation mutants. We have developed new combines systems loss-of-binding missense single step. strategy used...