|Description||Donkey Anti-Goat IgG Antibody, Species Adsorbed|
|Presentation||Liquid in 0.1M Sodium Phosphate, 0.25M NaCl, pH 7.6|
|Safety Information according to GHS|
|Storage and Shipping Information|
|Storage Conditions||Store product at 2-8'C under sterile conditions for up to 12 months.|
|Material Size||1 mL|
|AFFINITY PURIFIED -2755749||2755749|
|AFFINITY PURIFIED SECONDARY ANTIBODY||3072886|
|ALKALINE PHOSPHATASE CONJUGATED -2686224||2686224|
|Reference overview||Application||Pub Med ID|
|GABA(B) receptors do not internalize after baclofen treatment, possibly due to a lack of β-arrestin association: study with a real-time visualizing assay.|
Yuka Sudo,Minoru Hojo,Yuko Ando,Masafumi Takada,Hiroaki Murata,Shinji Kurata,Noriyuki Nishida,Yasuhito Uezono
Synapse (New York, N.Y.) 66 2012
The mechanism of agonist-induced GABA(B) receptor (GABA(B) R) internalization is not well understood. To investigate this process, we focused on the interaction of GABA(B) R with β-arrestins, which are key proteins in the internalization of most of the G protein-coupled receptors, and the agonist-induced GABA(B) R internalization and the interaction of GABA(B) R with β-arrestin1 and β-arrestin2 were investigated in real time using GABA(B) R and β-arrestins both of which were fluorescent protein-tagged. We then compared these profiles with those of μ-opioid receptors (μOR), well-studied receptors that associate and cointernalize with β-arrestins. When stimulated by the specific GABA(B) R agonist baclofen, GABA(B) R composed of GABA(B1a) R (GB(1a) R) and fluorescent protein-tagged GABA(B2) R-Venus (GB₂ R-V) formed functional GABA(B) R; they elicited G protein-activated inwardly rectifying potassium channels as well as nontagged GABA(B) R. In cells coexpressing GB(1a) R, GB₂ R-V, and β-arrestin1-Cerulean (βarr1-C) or β-arrestin2-Cerulean (βarr2-C), real-time imaging studies showed that baclofen treatment neither internalized GB₂ R-V nor mobilized βarr1-C or βarr2-C to the cell surface. This happened regardless of the presence of G protein-coupled receptor kinase 4 (GRK4), which forms a complex with GABA(B) R and causes GABA(B) R desensitization. On the other hand, in cells coexpressing μOR-Venus, GRK2, and βarr1-C or βarr2-C, the μOR molecule formed μOR/βarr1 or μOR/βarr2 complexes on the cell surface, which were then internalized into the cytoplasm in a time-dependent manner. Fluorescence resonance energy transfer assay also indicated scarce association of GB₂ R-V and β-arrestins-C with or without the stimulation of baclofen, while robust association of μOR-V with β-arrestins-C was detected after μOR activation. These findings suggest that GABA(B) Rs failure to undergo agonist-induced internalization results in part from its failure to interact with β-arrestins.
|Interactome of the Amyloid Precursor Protein APP in Brain Reveals a Protein Network Involved in Synaptic Vesicle Turnover and a Close Association with Synaptotagmin-1.|
Bernhard M Kohli,Delphine Pflieger,Lukas N Mueller,Giovanni Carbonetti,Ruedi Aebersold,Roger M Nitsch,Uwe Konietzko
Journal of proteome research 11 2012
Knowledge of the protein networks interacting with the amyloid precursor protein (APP) in vivo can shed light on the physiological function of APP. To date, most proteins interacting with the APP intracellular domain (AICD) have been identified by Yeast Two Hybrid screens which only detect direct interaction partners. We used a proteomics-based approach by biochemically isolating tagged APP from the brains of transgenic mice and subjecting the affinity-purified complex to mass spectrometric (MS) analysis. Using two different quantitative MS approaches, we compared the protein composition of affinity-purified samples isolated from wild-type mice versus transgenic mice expressing tagged APP. This enabled us to assess truly enriched proteins in the transgenic sample and yielded an overlapping set of proteins containing the major proteins involved in synaptic vesicle endo- and exocytosis. Confocal microscopy analyses of cotransfected primary neurons showed colocalization of APP with synaptic vesicle proteins in vesicular structures throughout the neurites. We analyzed the interaction of APP with these proteins using pulldown experiments from transgenic mice or cotransfected cells followed by Western blotting. Synaptotagmin-1 (Stg1), a resident synaptic vesicle protein, was found to directly bind to APP. We fused Citrine and Cerulean to APP and the candidate proteins and measured fluorescence resonance energy transfer (FRET) in differentiated SH-SY5Y cells. Differentially tagged APPs showed clear sensitized FRET emission, in line with the described dimerization of APP. Among the candidate APP-interacting proteins, again only Stg1 was in close proximity to APP. Our results strongly argue for a function of APP in synaptic vesicle turnover in vivo. Thus, in addition to the APP cleavage product Aβ, which influences synaptic transmission at the postsynapse, APP interacts with the calcium sensor of synaptic vesicles and might thus play a role in the regulation of synaptic vesicle exocytosis.
|Amyloidogenic Properties of a DN Mutated 12 Amino Acid Fragment of the C-Terminal Domain of the Cholesteryl-Ester Transfer Protein (CETP).|
García-González V, Mas-Oliva J.
International journal of molecular sciences 12 2019-35 2011
The cholesteryl-ester transfer protein (CETP) facilitates the transfer of cholesterol esters and triglycerides between lipoproteins in plasma where the critical site for its function is situated in the C-terminal domain. Our group has previously shown that this domain presents conformational changes in a non-lipid environment when the mutation D(470)N is introduced. Using a series of peptides derived from this C-terminal domain, the present study shows that these changes favor the induction of a secondary β-structure as characterized by spectroscopic analysis and fluorescence techniques. From this type of secondary structure, the formation of peptide aggregates and fibrillar structures with amyloid characteristics induced cytotoxicity in microglial cells in culture. These supramolecular structures promote cell cytotoxicity through the formation of reactive oxygen species (ROS) and change the balance of a series of proteins that control the process of endocytosis, similar to that observed when β-amyloid fibrils are employed. Therefore, a fine balance between the highly dynamic secondary structure of the C-terminal domain of CETP, the net charge, and the physicochemical characteristics of the surrounding microenvironment define the type of secondary structure acquired. Changes in this balance might favor misfolding in this region, which would alter the lipid transfer capacity conducted by CETP, favoring its propensity to substitute its physiological function.
|Phytic acid as a potential treatment for alzheimer's pathology: evidence from animal and in vitro models.|
Thimmappa S Anekonda,Teri L Wadsworth,Robert Sabin,Kate Frahler,Christopher Harris,Babett Petriko,Martina Ralle,Randy Woltjer,Joseph F Quinn
Journal of Alzheimer's disease : JAD 23 2011
Alzheimer's disease (AD) causes progressive, age-dependent cortical and hippocampal dysfunction leading to abnormal intellectual capacity and memory. We propose a novel protective treatment for AD pathology with phytic acid (inositol hexakisphosphate), a phytochemical found in food grains and a key signaling molecule in mammalian cells. We evaluated the protective and beneficial effects of phytic acid against amyloid-? (A?) pathology in MC65 cells and the Tg2576 mouse model. In MC65 cells, 48-72-hour treatment with phytic acid provided complete protection against amyloid precursor protein-C-terminal fragment-induced cytotoxicity by attenuating levels of increased intracellular calcium, hydrogen peroxide, superoxide, A? oligomers, and moderately upregulated the expression of autophagy (beclin-1) protein. In a tolerance paradigm, wild type mice were treated with 2% phytic acid in drinking water for 70 days. Phytic acid was well tolerated. Ceruloplasmin activity, brain copper and iron levels, and brain superoxide dismutase and ATP levels were unaffected by the treatment. There was a significant increase in brain levels of cytochrome oxidase and a decrease in lipid peroxidation with phytic acid administration. In a treatment paradigm, 12-month old Tg2576 and wild type mice were treated with 2% phytic acid or vehicle for 6 months. Brain levels of copper, iron, and zinc were unaffected. The effects of phytic acid were modest on the expression of A?PP trafficking-associated protein AP180, autophagy-associated proteins (beclin-1, LC3B), sirtuin 1, the ratio of phosphorylated AMP-activated protein kinase (PAMPK) to AMPK, soluble A?1-40, and insoluble A?1-42. These results suggest that phytic acid may provide a viable treatment option for AD.Full Text Article
|The tSP Motif in aP180 inhibits phospholipase d1 activity resulting in increased efficacy of anticancer drug via its direct binding to carboxyl terminal of phospholipase d1.|
Cho JH, Oh DY, Kim HJ, Park SY, Choi HJ, Kwon SJ, Lee KS, Han JS
Cancer letters 302 144-54. Epub 2011 Feb 5. 2011
Phospholipase D (PLD) has two isoforms, PLD1 and PLD2. Both isoforms are possible candidates for the development of anticancer drugs, since PLDs in several cancer cells act as survival factors. The aim of this study was to elucidate the inhibitory mechanism of PLD1 by AP180 in human cancer cells. Transfection of the human AP180 (hAP180) gene markedly inhibited phobol-12-myristate 13-acetate-induced PLD activity resulting in exacerbation of anticancer drug-induced cell death. Experiments using deletion mutants of hAP180 showed that three amino acids (Thr312-Pro314) are critical for inhibition of PLD1 activity by binding directly to PLD1, and, of these, Ser313 was the most important residue for both binding to and inhibiting PLD1. However, this inhibitory relationship did not exist between hAP180 and PLD2. In addition, the C-terminal region of PLD1 is important for the interaction with hAP180. These results indicated that Thr312-Pro314 (especially Ser313 as a phosphorylation residue) of hAP180 can regulate hPLD1 activity through binding with the C-terminal region of PLD1.Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
|Identification of Contractile Vacuole Proteins in Trypanosoma cruzi.|
Ulrich PN, Jimenez V, Park M, Martins VP, Atwood J, Moles K, Collins D, Rohloff P, Tarleton R, Moreno SN, Orlando R, Docampo R
PLoS One 6 e18013. 2011
Contractile vacuole complexes are critical components of cell volume regulation and have been shown to have other functional roles in several free-living protists. However, very little is known about the functions of the contractile vacuole complex of the parasite Trypanosoma cruzi, the etiologic agent of Chagas disease, other than a role in osmoregulation. Identification of the protein composition of these organelles is important for understanding their physiological roles. We applied a combined proteomic and bioinfomatic approach to identify proteins localized to the contractile vacuole. Proteomic analysis of a T. cruzi fraction enriched for contractile vacuoles and analyzed by one-dimensional gel electrophoresis and LC-MS/MS resulted in the addition of 109 newly detected proteins to the group of expressed proteins of epimastigotes. We also identified different peptides that map to at least 39 members of the dispersed gene family 1 (DGF-1) providing evidence that many members of this family are simultaneously expressed in epimastigotes. Of the proteins present in the fraction we selected several homologues with known localizations in contractile vacuoles of other organisms and others that we expected to be present in these vacuoles on the basis of their potential roles. We determined the localization of each by expression as GFP-fusion proteins or with specific antibodies. Six of these putative proteins (Rab11, Rab32, AP180, ATPase subunit B, VAMP1, and phosphate transporter) predominantly localized to the vacuole bladder. TcSNARE2.1, TcSNARE2.2, and calmodulin localized to the spongiome. Calmodulin was also cytosolic. Our results demonstrate the utility of combining subcellular fractionation, proteomic analysis, and bioinformatic approaches for localization of organellar proteins that are difficult to detect with whole cell methodologies. The CV localization of the proteins investigated revealed potential novel roles of these organelles in phosphate metabolism and provided information on the potential participation of adaptor protein complexes in their biogenesis.Full Text Article
|A novel post-translational modification in nerve terminals: O-linked N-acetylglucosamine phosphorylation.|
Mark E Graham,Morten Thaysen-Andersen,Nicolai Bache,George E Craft,Martin R Larsen,Nicolle H Packer,Phillip J Robinson
Journal of proteome research 10 2011
Protein phosphorylation and glycosylation are the most common post-translational modifications observed in biology, frequently on the same protein. Assembly protein AP180 is a synapse-specific phosphoprotein and O-linked beta-N-acetylglucosamine (O-GlcNAc) modified glycoprotein. AP180 is involved in the assembly of clathrin coated vesicles in synaptic vesicle endocytosis. Unlike other types of O-glycosylation, O-GlcNAc is nucleocytoplasmic and reversible. It was thought to be a terminal modification, that is, the O-GlcNAc was not found to be additionally modified in any way. We now show that AP180 purified from rat brain contains a phosphorylated O-GlcNAc (O-GlcNAc-P) within a highly conserved sequence. O-GlcNAc or O-GlcNAc-P, but not phosphorylation alone, was found at Thr-310. Analysis of synthetic GlcNAc-6-P produced identical fragmentation products to GlcNAc-P from AP180. Direct O-linkage of GlcNAc-P to a Thr residue was confirmed by electron transfer dissociation MS. A second AP180 tryptic peptide was also glycosyl phosphorylated, but the site of modification was not assigned. Sequence similarities suggest there may be a common motif within AP180 involving glycosyl phosphorylation and dual flanking phosphorylation sites within 4 amino acid residues. This novel type of protein glycosyl phosphorylation adds a new signaling mechanism to the regulation of neurotransmission and more complexity to the study of O-GlcNAc modification.
|Macropinocytotic uptake and infection of human epithelial cells with species B2 adenovirus type 35.|
Kälin S, Amstutz B, Gastaldelli M, Wolfrum N, Boucke K, Havenga M, DiGennaro F, Liska N, Hemmi S, Greber UF
J Virol 84 5336-50. Epub 2010 Mar 17. 2010
Human adenovirus serotype 35 (HAdV-35; here referred to as Ad35) causes kidney and urinary tract infections and infects respiratory organs of immunocompromised individuals. Unlike other adenoviruses, Ad35 has a low seroprevalence, which makes Ad35-based vectors promising candidates for gene therapy. Ad35 utilizes CD46 and integrins as receptors for infection of epithelial and hematopoietic cells. Here we show that infectious entry of Ad35 into HeLa cells, human kidney HK-2 cells, and normal human lung fibroblasts strongly depended on CD46 and integrins but not heparan sulfate and variably required the large GTPase dynamin. Ad35 infections were independent of expression of the carboxy-terminal domain of AP180, which effectively blocks clathrin-mediated uptake. Ad35 infections were inhibited by small chemicals against serine/threonine kinase Pak1 (p21-activated kinase), protein kinase C (PKC), sodium-proton exchangers, actin, and acidic organelles. Remarkably, the F-actin inhibitor jasplakinolide, the Pak1 inhibitor IPA-3, or the sodium-proton exchange inhibitor 5-(N-ethyl-N-isopropyl) amiloride (EIPA) blocked endocytic uptake of Ad35. Dominant-negative proteins or small interfering RNAs against factors driving macropinocytosis, including the small GTPase Rac1, Pak1, or the Pak1 effector C-terminal binding protein 1 (CtBP1), potently inhibited Ad35 infection. Confocal laser scanning microscopy, electron microscopy, and live cell imaging showed that Ad35 colocalized with fluid-phase markers in large endocytic structures that were positive for CD46, alphanu integrins, and also CtBP1. Our results extend earlier observations with HAdV-3 (Ad3) and establish macropinocytosis as an infectious pathway for species B human adenoviruses in epithelial and hematopoietic cells.Full Text Article
|Distribution and expression of picalm in Alzheimer disease.|
Baig S, Joseph SA, Tayler H, Abraham R, Owen MJ, Williams J, Kehoe PG, Love S
J Neuropathol Exp Neurol 69 1071-7. 2010
PICALM, the gene encoding phosphatidylinositol-binding clathrin assembly (picalm) protein, was recently shown to be associated with risk of Alzheimer disease (AD). Picalm is a key component of clathrin-mediated endocytosis. It recruits clathrin and adaptor protein 2 (AP-2) to the plasma membrane and, along with, AP-2 recognizes target proteins. The attached clathrin triskelions cause membrane deformation around the target proteins enclosing them within clathrin-coated vesicles to be processed in lysosomes or endosomes. We examined the distribution of picalm in control and AD brain tissue and measured levels of picalm messenger RNA (mRNA) by real-time polymerase chain reaction. Immunolabeling of brain tissue showed that picalm is predominately present in endothelial cells. This was further supported by the demonstration of picalm in human cerebral microvascular cells grown in culture. Picalm mRNA was elevated in relation to glyceraldehyde-3-phosphate dehydrogenase but not factor VIII-related antigen or CD31 mRNA in the frontal cortex in AD. No change was seen in the temporal cortex or thalamus. The transport of Aβ across vessel walls and into the bloodstream is a major pathway of Aβ removal from the brain and picalm is ideally situated within endothelial cells to participate in this process. Further research is needed to determine whether PICALM expression is influenced by Aβ levels and whether it affects Aβ uptake and transport by endothelial cells.
|Dynamic Interactions between Clathrin and Locally Structured Elements in a Disordered Protein Mediate Clathrin Lattice Assembly.|
Zhuo Y, Ilangovan U, Schirf V, Demeler B, Sousa R, Hinck AP, Lafer EM
J Mol Biol 2010
Assembly of clathrin lattices is mediated by assembly/adaptor proteins that contain domains that bind lipids or membrane-bound cargo proteins and clathrin binding domains (CBDs) that recruit clathrin. Here, we characterize the interaction between clathrin and a large fragment of the CBD of the clathrin assembly protein AP180. Mutational, NMR chemical shift, and analytical ultracentrifugation analyses allowed us to precisely define two clathrin binding sites within this fragment, each of which is found to bind weakly to the N-terminal domain of the clathrin heavy chain (TD). The locations of the two clathrin binding sites are consistent with predictions from sequence alignments of previously identified clathrin binding elements and, by extension, indicate that the complete AP180 CBD contains ∼12 degenerate repeats, each containing a single clathrin binding site. Sequence and circular dichroism analyses have indicated that the AP180 CBD is predominantly unstructured and our NMR analyses confirm that this is largely the case for the AP180 fragment characterized here. Unexpectedly, unlike the many proteins that undergo binding-coupled folding upon interaction with their binding partners, the AP180 fragment is similarly unstructured in its bound and free states. Instead, we find that this fragment exhibits localized β-turn-like structures at the two clathrin binding sites both when free and when bound to clathrin. These observations are incorporated into a model in which weak binding by multiple, pre-structured clathrin binding elements regularly dispersed throughout a largely unstructured CBD allows efficient recruitment of clathrin to endocytic sites and dynamic assembly of the clathrin lattice.
|Donkey anti-Goat IgG, Species Adsorbed: Hu, Ms, Rt, Chk, GP, Eq, Hmst, Rb - Data Sheet|