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Biological Chemistry

Panagiotis S Athanasopoulos, Rolf Heumann, Arjan Kortholt
Mutations in human leucine-rich-repeat kinase 2 (LRRK2) have been found to be the most frequent cause of late-onset Parkinson's Disease (PD). LRRK2 is a large protein with two enzymatic domains, a GTPase and a kinase domain. A cluster of (auto)-phosphorylation sites within the N-terminus of LRRK2 have been shown to be crucial for the localization of LRRK2 and is important for PD pathogenesis. In addition, phosphorylation of sites within the G-domain of the protein affect GTPase activity. Here we discuss the role of these (auto)-phosphorylation sites of LRRK2 and their regulation by phosphatases and upstream kinases...
March 12, 2018: Biological Chemistry
Libin Zhang, Liang Bu, Jiang Hu, Zheyuan Xu, Libo Ruan, Yan Fang, Ping Wang
Non-small cell lung cancer (NSCLC) is a common malignant tumor. Although the abnormal expression and potential clinical prognostic value of histone deacetylase 1 (HDAC1) were recently discovered in many kinds of cancer, the roles and molecular mechanisms of HDAC1 in NSCLC is still limited. The CCK-8 assay is used to evaluate the viability of NSCLC cells. Downregulation of HDAC1 by shRNA. The TUNEL assay was used to evaluate the role of HDAC1 in NSCLC apoptosis. To evaluate the role of HDAC1 in NSCLC cells migration, the Boyden chamber transwell assay and wound healing assay were used...
March 12, 2018: Biological Chemistry
Bianca Schrul, Wolfgang Schliebs
In order to adapt to environmental changes, such as nutrient availability, cells have to orchestrate multiple metabolic pathways, which are catalyzed in distinct specialized organelles. Lipid droplets (LDs) and peroxisomes are both endoplasmic reticulum-derived organelles that fulfill complementary functions in lipid metabolism: Upon nutrient supply, LDs store metabolic energy in the form of neutral lipids and, when energy is needed, supply fatty acids for oxidation in peroxisomes and mitochondria. How these organelles communicate with each other for a concerted metabolic output remains a central question...
March 1, 2018: Biological Chemistry
Simone Fulda
Macroautophagy (herein termed autophagy) is evolutionarily highly conserved across eukaryotic cells and represents an intracellular catabolic process that targets damaged macromolecules and organelles for degradation. Autophagy is dysregulated in various human diseases including cancer. In addition, many drugs currently used for the treatment of cancer can engage autophagy, which typically promotes cancer cell survival by mitigating cellular stress. However, under certain circumstances activation of autophagy upon anticancer drug treatment can also trigger a lethal type of autophagy termed autophagic cell death (ACD)...
March 1, 2018: Biological Chemistry
Karen Jülicher, Annabell Wähner, Kerstin Haase, Karen W Barbour, Franklin G Berger, Lutz Wiehlmann, Colin Davenport, Karin Schuster-Gossler, Jörn Stitz, Tobias Cantz, Reto Eggenschwiler
The generation of authentic mouse-models for human α1-antitrypsin-deficiency is difficult due to the high complexity of the mouse Serpina1 gene locus. Depending on the exact mouse strain, three to five paralogs are expressed, with different proteinase inhibitory properties. With nowadays CRISPR-technology, genome editing of complex genomic loci is feasible and could be employed for generation of α1-antitrypsin-deficiency mouse-models. In preparation of a CRISPR/Cas9-based genome-engineering approach we identified cDNA clones with a functional CDS for the Serpina1-paralog DOM-7...
March 1, 2018: Biological Chemistry
Siwei Liu, Huajiang Lei, Fangyuan Luo, Yilin Li, Lan Xie
This study aimed at investigating the biological functions of long non-coding RNAs (lncRNAs) hox transcript antisense intergenic RNA (HOTAIR) in resistant ovarian cancer cells, exploring the regulation effect of HOTAIR on HOXA7, and investigating their influence on the chemosensitivity of ovarian cancer cells. Quantitative real-time polymerase chain reaction (qRT-PCR) was applied for the verification of HOTAIR expression in resistant and sensitive groups. How HOTAIR downregulation affected cell proliferation, migration and invasion, and apoptosis were determined using the MTT assay and the colony formation assay, the Transwell assay and flow cytometry analysis, respectively...
February 19, 2018: Biological Chemistry
David Ulbricht, Catherine A Tindall, Kathrin Oertwig, Stefanie Hanke, Norbert Sträter, John T Heiker
Kallikrein-related peptidases KLK5, KLK7 and KLK14 are important proteases in skin desquamation and aberrant KLK activity is associated with inflammatory skin diseases such as Netherton syndrome but also with various serious forms of cancer. Previously, we have identified KLK7 as the first protease target of vaspin (Serpin A12). Here, we report KLK14 as a second KLK protease to be inhibited by vaspin. In conclusion, vaspin represents a multispecific serpin targeting the kallikrein proteases KLK7 and KLK14, with distinct exosites regulating recognition of these target proteases and opposing effects of heparin binding on the inhibition reaction...
February 1, 2018: Biological Chemistry
Kelei Li, Zhe Cong, Zhuoying Peng, Ting Chen, Jing Xue, Qiang Wei
CD45 has been reported to regulate the HIV-1 gp120-induced apoptosis of Jurkat cells. Here, we demonstrate that the extracellular domain of CD45 plays an important role in this function. We observed that CD45RO-transfected cells, but not cells transfected with other CD45 isoforms, underwent significant apoptosis induced by gp120. However, a CD45RA-transfected cell line treated with an O-glycan inhibitor was able to undergo apoptosis. The role of the extracellular domain of CD45 was further confirmed using CD45 isoformtransfected cell lines by analyzing the phosphorylation of Lck, which is a direct substrate of CD45 tyrosine phosphatase, and by using an Lck inhibitor...
December 20, 2017: Biological Chemistry
Hans G Drexler, Claudia Pommerenke, Sonja Eberth, Stefan Nagel
A characteristic component of the Hodgkin lymphoma (HL) tissue are the mono- or multinucleated Hodgkin-Reed-Sternberg (HRS) cells. Given the challenges of isolating these rare malignant cells and the difficulty in culturing cells from patients, many investigators have tried to establish cell lines in efforts to develop cellular tools for in vitro studies. A limited number of HL cell lines exist and have provided valuable insights into HL pathobiology. A literature survey indicated that 35 cell lines derived from HL patients have been published...
December 20, 2017: Biological Chemistry
Meriem Haddada, Hend Draoui, Lydia Deschamps, Francine Walker, Tiphaine Delaunay, Maria Brattsand, Viktor Magdolen, Dalila Darmoul
We recently reported that human melanoma cells, but not benign melanocytes, aberrantly express kallikrein-related peptidase 7 (KLK7). Here, we show a KLK7 over expression-mediated decrease of cell adhesion to extracellular matrix binding proteins, associated with down-regulation of α5/β1/αv/β3 integrin expression. We also report an up-regulation of MCAM/CD146 and an increase in spheroid formation of these cells. Our results demonstrate that aberrant KLK7 expression leads to a switch to a more malignant phenotype suggesting a potential role of KLK7 in melanoma invasion...
December 20, 2017: Biological Chemistry
Andrea Princz, Konstantinos Kounakis, Nektarios Tavernarakis
Mitochondria are critical to tissues and organs characterized by high-energy demands, such as the nervous system. They provide essential energy and metabolites, and maintain Ca2+ balance, which is imperative for proper neuronal function and development. Emerging findings further underline the role of mitochondria in neurons. Technical advances in the last decades made it possible to investigate key mechanisms in neuronal development and the contribution of mitochondria therein. In this article, we discuss the latest findings relevant to the involvement of mitochondria in neuronal development, placing emphasis on mitochondrial metabolism and dynamics...
December 20, 2017: Biological Chemistry
Daniela Schmid, Annette Buntz, Thi Ngoc Hanh Phan, Klaus Mayer, Eike Hoffmann, Irmgard Thorey, Jens Niewöhner, Katrin Vasters, Ranjan Sircar, Olaf Mundigl, Roland E Kontermann, Ulrich Brinkmann
A transcellular shuttle system was generated for delivery of non-covalently linked payloads across blood-brain-barrier (BBB) endothelial cells. Transcytosis enabling shuttles are composed of bispecific antibodies (bsAbs) that simultaneously bind transferrin receptor (TfR) and haptens such as digoxigenin or biocytinamide. Haptenylated payloads are attached to these vehicles via non-covalent hapten-antibody complexation. This enables targeting to and internalization into human BBB-derived microvascular endothelial HCMEC/D3 cells...
December 20, 2017: Biological Chemistry
Yuanyuan Meng, Qi Li, Lianwei Li, Rong Ma
This study was intended to analyze effects of lncRNA CRNDE on cervical cancer cell growth and metastasis. Fifty pairs of cervical cancer tissues and corresponding adjacent tissues were collected. Expressions of long non-coding RNAs (lncRNAs) in tissue samples were detected by microarray analysis. Expression levels of CRNDE in cervical cancer cells and normal cells were detected by qRT-PCR. Cell-counting kit-8 (CCK-8) assay and clone formation assay were utilized to evaluate cell growth. Wound healing assay and Transwell assay were conducted to detect the migratory and invasive capability of cervical cancer cells...
December 20, 2017: Biological Chemistry
Marcel Zimmermann, Andreas S Reichert
Mitochondria are indispensable cellular organelles providing ATP and numerous other essential metabolites to ensure cell survival. Reactive oxygen species (ROS), which are formed as side reactions during oxidative phosphorylation or by external agents, induce molecular damage in mitochondrial proteins, lipids/membranes and DNA. To cope with this and other sorts of organellar stress, a multi-level quality control system exists to maintain cellular homeostasis. One critical level of mitochondrial quality control is the removal of damaged mitochondria by mitophagy...
December 20, 2017: Biological Chemistry
Jorge Cuellar, José María Valpuesta, Alfred Wittinghofer, Begoña Sot
Rasal is a modular multi-domain protein of the GTPase-activating protein 1 (GAP1) family; its four known members, GAP1m, Rasal, GAP1IP4BP and Capri, have a Ras GTPase-activating domain (RasGAP). This domain supports the intrinsically slow GTPase activity of Ras by actively participating in the catalytic reaction. In the case of Rasal, GAP1IP4BP and Capri, their remaining domains are responsible for converting the RasGAP domains into dual Ras- and Rap-GAPs, via an incompletely understood mechanism. Although Rap proteins are small GTPase homologues of Ras, their catalytic residues are distinct, which reinforces the importance of determining the structure of full-length GAP1 family proteins...
December 20, 2017: Biological Chemistry
Monika B Dolinska, Yuri V Sergeev
Tyrosinase, a melanosomal glycoenzyme, catalyzes initial steps of the melanin biosynthesis. While glycosylation was previously studied in vivo, we present three recombinant mutant variants of human tyrosinase, which were obtained using multiple site-directed mutagenesis, expressed in insect larvae, purified and characterized biochemically. The mutagenesis demonstrated the reduced protein expression and enzymatic activity due to possible loss of protein stability and protein degradation. However, the complete deglycosylation of asparagine residues in vitro, including the residue in position 371, interrupts tyrosinase function, which is consistent with a melanin loss in oculocutaneous albinism type 1 (OCA1) patients...
December 20, 2017: Biological Chemistry
Simonas Savickas, Ulrich Auf dem Keller
Targeted degradomics integrates positional information into mass spectrometry (MS)-based targeted proteomics workflows and thereby enables analysis of proteolytic cleavage events with unprecedented specificity and sensitivity. Rapid progress in the establishment of protease-substrate relations provides extensive degradomics target lists that now can be tested with help of selected and parallel reaction monitoring (S/PRM) in complex biological systems, where proteases act in physiological environments. In this minireview, we describe the general principles of targeted degradomics, outline the generic experimental workflow of the methodology and highlight recent and future applications in protease research...
December 20, 2017: Biological Chemistry
Louise A Stephen, Yasmin Elmaghloob, Shehab Ismail
The primary cilium is a sensory organelle that is vital in regulating several signalling pathways. Unlike most organelles cilia are open to the rest of the cell, not enclosed by membranes. The distinct protein composition is crucial to the function of cilia and many signalling proteins and receptors are specifically concentrated within distinct compartments. To maintain this composition, a mechanism is required to deliver proteins to the cilium whilst another must counter the entropic tendency of proteins to distribute throughout the cell...
December 20, 2017: Biological Chemistry
Nguyen Thi Thanh Ho, Arne Kutzner, Klaus Heese
Due to an aging society with an increased dementia-induced threat to higher cognitive functions, it has become imperative to understand the molecular and cellular events controlling the memory and learning processes in the brain. Here, we suggest that the novel master gene pair |-SRGAP2-FAM72-| (SLIT-ROBO Rho GTPase activating the protein 2, family with sequence similarity to 72) reveals a new dogma for the regulation of neural stem cell (NSC) gene expression and is a distinctive player in the control of human brain plasticity...
December 20, 2017: Biological Chemistry
Kamila Tomoko Yuyama, Diana Fortkamp, Wolf-Rainer Abraham
Eremophilanes are sesquiterpenes with a rearranged carbon skeleton formed both by plants and fungi, however, almost no plant eremophilanes are found in fungi. These eremophilanes possess mainly phytotoxic, antimicrobial, anticancer and immunomodulatory properties and in this review fungal eremophilanes with bioactivities of potential medicinal applications are reviewed and discussed. A special focus is set on natural products bearing highly functionalized fatty acids at C-1 or C-3 position of the eremophilane backbone...
December 20, 2017: Biological Chemistry
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