Architecture of coatomer: Molecular characterization of delta-COP and protein interactions within the complex

Copyright © 2011 by The Rockefeller University Press.Coatomer is a cytosolic protein complex that forms the coat of COP I-coated transport vesicles. In our attempt to analyze the physical and functional interactions between its seven subunits (coat proteins, [COPs] alpha-zeta), we engaged in a program to clone and characterize the individual coatomer subunits. We have now cloned, sequenced, and overexpressed bovine alpha-COP, the 135-kD subunit of coatomer as well as delta-COP, the 57-kD subunit and have identified a yeast homolog of delta-COP by cDNA sequence comparison and by NH2-terminal peptide sequencing. delta-COP shows homologies to subunits of the clathrin adaptor complexes AP1 and AP2. We show that in Golgi-enriched membrane fractions, the protein is predominantly found in COP I-coated transport vesicles and in the budding regions of the Golgi membranes. A knock-out of the delta-COP gene in yeast is lethal. Immunoprecipitation, as well as analysis exploiting the two-hybrid system in a complete COP screen, showed physical interactions between alpha- and epsilon-COPs and between beta- and delta-COPs. Moreover, the two-hybrid system indicates interactions between gamma- and zeta-COPs as well as between alpha- and beta' COPs. We propose that these interactions reflect in vivo associations of those subunits and thus play a functional role in the assembly of coatomer and/or serve to maintain the molecular architecture of the complex.This work was supported by The Deutsche Forschungsgemeinschaft (SFB 352), the Human Frontier Science Program, and the Swiss National Science Foundation No. 31-43366.95

The primary structure of three hemoglobin chains from the indigo snake (Drymarchon corais erebennus, Serpentes): First evidence for αD chains and two β chain types in snakes

The hemoglobin of the indigo snake (Drymarchon corais erebennus, Colubrinae) consists of two components, HbA and HbD, in the ratio of 1:1. They differ in both their alpha and beta chains. The amino acid sequences of both alpha chains (alpha(A) and alpha(D)) and one beta chain (betaI) were determined. The presence of an alpha(D)chain in a snake hemoglobin is described for the first time. A comparison of all snake beta chain sequences revealed the existence of two paralogous beta chain types in snakes as well, which are designated as betaI and betaII type. For the discussion of the physiological properties of Drymarchon hemoglobin, the sequences were compared with those of the human alpha and beta chains and those of the closely related water snake Liophis miliaris where functional data are available. Among the heme contacts, the substitution alpha(D)58(E7)His-->Gln is unusual but most likely without any effect. The residues responsible for the main part of the Bohr effect are the same as in mammalian hemoglobins. In each of the three globin chains only two residues at positions involved in the alpha1/beta2 interface contacts, most important for the stability and the properties of the hemoglobin molecule, are substituted with regard to human hemoglobin. On the contrary, nine, eleven, and six alpha1/beta1 contact residues are replaced in the alpha(A), alpha(D), betaI chains, respectively

ICPL_ESIQuant – a Powerful Freeware Tool for Handling Proteomics LCESI- MS2 Experiments

Among the MS-based quantitative methods using stable isotope labelling, the Isotope-Coded Protein Label (ICPL) technique has emerged as a powerful tool to identify and relatively quantify thousands of proteins within complex protein mixtures. The ICPL_ESIQuant 3.0 software package is one of the key components of the ICPL-ESI workflow, covering data processing steps like LC-MS feature detection, ICPL doublet/triplet/quadruplet quantification as well as a merging step of LC-MS features and Mascot search results. As unique features, the software performs isotope pattern overlap corrections and utilizes additional chemical knowledge, e.g. the physico-chemical properties of the ICPL labels, to discard false positive isotope pattern, which significantly improves the quality of the final peptide and protein results. ICPL_ESIQuant is the first freeware tool on the market, which supports both the shotgun proteomics strategy using Data Dependent Acquisition (DDA) and the directed proteomics strategy using mass inclusion lists for precursor ion selection. ICPL_ESIQuant 3.0 (32 and 64 bit versions) can be downloaded from https://sourceforge.net/projects/icplquant/ files

Women With Congenital Adrenal Hyperplasia Have Favorable Pregnancy Outcomes but Prolonged Time to Conceive

OBJECTIVE To study pregnancy outcomes and complications in women with congenital adrenal hyperplasia (CAH). METHODS A retrospective multicenter study was conducted at tertiary reference centers in 5 countries (Austria, Germany, Italy, Sweden, USA), including 72 adult women with CAH (nonclassic [NC] n = 34, simple virilizing [SV] n = 21, salt wasting [SW] n = 17). RESULTS A total of 133 pregnancies, 112 live births, and 25 abortions were documented. Prolonged latency to pregnancy was observed (median 11 months in SW, 24 months in SV, 8 months in NC), with a notable use of fertility-enhancing medication (25.6%) and assisted reproductive techniques (30.8%). Over half of the women in each group took more than 12 months to conceive. The average number of live births (1.4-1.6 children per woman) was similar across CAH phenotypes and comparable to the general population. Spontaneous abortion rates (18.0%) were also similar across phenotypes. Primary cesarean section rates (60.9%) were higher than in the general population, though 23.8% of women with SV and 29.4% of women with SW gave birth naturally, despite most having undergone genital surgery. Children categorized as small for gestational age were 20.5%. Pregnancy, delivery, and postpartum complications were rare for mothers and neonates. CONCLUSION The study indicates a prolonged latency to pregnancy and high use of fertility treatments in CAH patients, regardless of phenotype. Abortion rates were not increased, and overall pregnancy and perinatal outcomes were favorable

Major immunophenotypic abnormalities in patients with primary adrenal insufficiency of different etiology

INTRODUCTION Patients with primary adrenal insufficiency (PAI) suffer from increased risk of infection, adrenal crises and have a higher mortality rate. Such dismal outcomes have been inferred to immune cell dysregulation because of unphysiological cortisol replacement. As the immune landscape of patients with different types of PAI has not been systematically explored, we set out to immunophenotype PAI patients with different causes of glucocorticoid (GC) deficiency. METHODS This cross-sectional single center study includes 28 patients with congenital adrenal hyperplasia (CAH), 27 after bilateral adrenalectomy due to Cushing's syndrome (BADx), 21 with Addison's disease (AD) and 52 healthy controls. All patients with PAI were on a stable GC replacement regimen with a median dose of 25 mg hydrocortisone per day. Peripheral blood mononuclear cells were isolated from heparinized blood samples. Immune cell subsets were analyzed using multicolor flow cytometry after four-hour stimulation with phorbol myristate acetate and ionomycin. Natural killer (NK-) cell cytotoxicity and clock gene expression were investigated. RESULTS The percentage of T helper cell subsets was downregulated in AD patients (Th1 p = 0.0024, Th2 p = 0.0157, Th17 p < 0.0001) compared to controls. Cytotoxic T cell subsets were reduced in AD (Tc1 p = 0.0075, Tc2 p = 0.0154) and CAH patients (Tc1 p = 0.0055, Tc2 p = 0.0012) compared to controls. NKCC was reduced in all subsets of PAI patients, with smallest changes in CAH. Degranulation marker CD107a expression was upregulated in BADx and AD, not in CAH patients compared to controls (BADx p < 0.0001; AD p = 0.0002). In contrast to NK cell activating receptors, NK cell inhibiting receptor CD94 was upregulated in BADx and AD, but not in CAH patients (p < 0.0001). Although modulation in clock gene expression could be confirmed in our patient subgroups, major interindividual-intergroup dissimilarities were not detected. DISCUSSION In patients with different etiologies of PAI, distinct differences in T and NK cell-phenotypes became apparent despite the use of same GC preparation and dose. Our results highlight unsuspected differences in immune cell composition and function in PAI patients of different causes and suggest disease-specific alterations that might necessitate disease-specific treatment

Cloning of a novel malignant melanoma-derived growth-regulatory protein, MIA

Growth and progression of malignant melanoma cells is influenced by a complex network of growth-stimulating and -inhibiting factors produced by both the tumor cells and the local environment. Here we report the purification and molecular cloning of a novel growth regulating protein, designated melanoma inhibitory activity (MIA) and provide a preliminary functional characterization. MIA is translated as a 131-amino acid precursor and processed into a mature 107-amino acid protein after cleavage of a putative secretion signal. A murine complementary DNA was isolated that encoded a MIA-protein with 88% amino acid identity. MIA is secreted into the culture supernatant by several malignant melanoma cell lines as an M(r) 11,000 autocrine growth factor and acts as a potent tumor cell growth inhibitor for malignant melanoma cells and some other neuroectodermal tumors, including gliomas. MIA has no homology to any other known protein and, therefore, represents a novel type of growth-regulatory factor. Furthermore, we describe a molecular approach to express functionally active MIA in Escherichia coli, which might be attractive as a future antitumor therapeutical substance