journal
MENU ▼
Read by QxMD icon Read
search

Journal of Biological Chemistry

journal
https://www.readbyqxmd.com/read/28634235/mechanistic-elucidation-of-the-mycofactocin-biosynthetic-radical-s-adenosylmethionine-protein-mftc
#1
Bulat Khaliullin, Richard Ayikpoe, Mason Tuttle, John A Latham
Ribosomally synthesized and posttranslationally modified peptide (RiPP) pathways produce a diverse array of natural products. A subset of these pathways depend on radical S-adenosylmethionine (RS) proteins to modify the RiPP-produced peptide. Mycofactocin biosynthesis is one example of an RS protein-dependent RiPP pathway. Recently, it has been shown that MftC catalyzes the oxidative decarboxylation of the C-terminal tyrosine (Tyr30) on the mycofactocin precursor peptide MftA; however, this product has not been verified by techniques other than MS...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28634234/the-thioreduction-component-ccmg-confers-efficiency-and-the-heme-ligation-component-ccmh-ensures-stereo-specificity-during-cytochrome-c-maturation
#2
Andreia F Verisssimo, Bahia Khalfaoui-Hassani, Josephine Hwang, Stefan Steimle, Nur Selamoglu, Carsten Sanders, Camilo Khatchikian, Fevzi Daldal
In many Gram-negative bacteria, including Rhodobacter capsulatus, cytochrome c maturation (Ccm) is carried out by a membrane-integral machinery composed of nine proteins (CcmA to I). During this process, the periplasmic thiol-disulfide oxidoreductase DsbA is thought to catalyze the formation of a disulfide bond between the Cys residues at the apocytochrome c heme binding site (CXXCH). Subsequently, a Ccm-specific thioreductive pathway involving CcmG and CcmH reduces this disulfide bond to allow covalent heme ligation...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28634233/structural-analyses-of-human-thymidylate-synthase-reveal-a-site-that-may-control-conformational-switching-between-active-and-inactive-states
#3
Dan Chen, Anna Jansson, Daniel Sim, Andreas Larsson, Pär Nordlund
Thymidylate synthase (TS) is the sole enzyme responsible for de novo biosynthesis of thymidylate (TMP) and is essential for cell proliferation and survival. Inhibition of human TS (hTS) has been extensively investigated for cancer chemotherapy, but several aspects of its activity and regulation are still uncertain. In this study, we performed comprehensive structural and biophysical studies of hTS using crystallography and thermal shift assay and provided the first detailed structural information on the conformational changes induced by ligand binding to the hTS active site...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28634232/the-phosphocarrier-protein-hpr-of-the-bacterial-phosphotransferase-system-globally-regulates-energy-metabolism-by-directly-interacting-with-multiple-enzymes-in-escherichia-coli
#4
Irina A Rodionova, Zhongge Zhang, Jitender Mehla, Norman Goodacre, Mohan Babu, Andrew Emili, Peter Uetz, Milton H Saier
The histidine-phosphorylatable phosphocarrier protein HPr, is an essential component of the sugar-transporting phosphotransferase system (PTS) in many bacteria. Recent interactome findings suggested that HPr interacts with several carbohydrate-metabolizing enzymes, but whether HPr plays a regulatory role was unclear. Here, we provide evidence that HPr interacts with a large number of proteins in Escherichia coli. We demonstrate HPr-dependent allosteric regulation of the activities of pyruvate kinase (PykF, but not PykA), phosphofructokinase (PfkB, but not PfkA), glucosamine 6-phosphate deaminase (NagB) and adenylate kinase (Adk)...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28634231/hyperactivity-of-the-arabidopsis-cryptochrome-cry1-l407f-mutant-is-caused-by-a-structural-alteration-close-to-the-cry1-atp-binding-sit
#5
Christian Orth, Nils Niemann, Lars Hennig, Lars-Oliver Essen, Alfred Batschauer
Plant cryptochromes (cry) act as UV-A/blue light receptors. The prototype, Arabidopsis thaliana cry1, regulates several light responses during the life cycle, including de-etiolation, and is also involved in regulating flowering time. The cry1 photocycle is initiated by light absorption by its FAD chromophore, which is most likely fully oxidized (FADox) in the dark state and photoreduced to the neutral flavin semiquinone (FADH(o)) in its lit state. Cryptochromes lack the DNA-repair activity of the closely related DNA photolyases, but retain the ability to bind nucleotides such as ATP...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28634230/similarity-in-gene-regulatory-networks-suggests-that-cancer-cells-share-characteristics-of-embryonic-neural-cells
#6
Zan Zhang, Anhua Lei, Liyang Xu, Lu Chen, Yonglong Chen, Xuena Zhang, Yan Gao, Xiaoli Yang, Min Zhang, Ying Cao
Cancer cells are immature cells resulting from cellular reprogramming by gene misregulation, and re-differentiation is expected to reduce malignancy. It is unclear, however, whether cancer cells can undergo terminal differentiation. Here, we show that, inhibition of the epigenetic modification enzymes enhancer of zeste homolog 2 (EZH2), histone deacetylases (HDACs) 1 and 3, lysine demethylase 1A (LSD1), or DNA methyltransferase 1 (DNMT1), which all promote cancer development and progression, leads to postmitotic neuron-like differentiation with loss of malignant features in distinct solid cancer cell lines...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28634229/akt-activation-by-ca2-calmodulin-dependent-protein-kinase-kinase-2-camkk2-in-ovarian-cancer-cells
#7
Angela M Gocher, Gissou Azabdaftari, Lindsey M Euscher, Shuhang Dai, Loukia G Karacosta, Thomas F Franke, Arthur M Edelman
Hyperactivation of Akt is associated with oncogenic changes in the growth, survival and chemoresistance of cancer cells. The PI3K/Phosphoinositide-dependent kinase (PDK) 1 pathway represents the canonical mechanism for phosphorylation of Akt at its primary activation site, Thr308. We observed that Ca2+/calmodulin (CaM)-dependent protein kinase kinase 2 (beta) (CaMKK2) is highly expressed in high-grade serous ovarian cancer and investigated its role in Akt activation in ovarian cancer (OVCa) cell lines (OVCAR-3, SKOV-3, Caov-3)...
June 20, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630045/structure-based-analysis-of-the-guanine-nucleotide-exchange-factor-smggds-reveals-armadillo-repeat-motifs-and-key-regions-for-activity-and-gtpase-binding
#8
Hikaru Shimizu, Sachiko Toma-Fukai, Shinya Saijo, Nobutaka Shimizu, Kenji Kontani, Toshiaki Katada, Toshiyuki Shimizu
Small GTPases are molecular switches that have critical biological roles and are controlled by GTPase-activating proteins and guanine-nucleotide exchange factors (GEFs). The smg GDP dissociation stimulator (SmgGDS) protein functions as a GEF for the RhoA and RhoC small GTPases. SmgGDS has various regulatory roles, including small GTPase trafficking and localization and as a molecular chaperone, and interacts with many small GTPases possessing polybasic regions. Two SmgGDS splice variants, SmgGDS-558 and SmgGDS-607, differ in GEF activity and binding affinity for RhoA depending on the lipidation state, but the reasons for these differences are unclear...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630044/single-molecule-fret-analysis-discloses-the-dynamics-of-the-dna-topoisomerase-ii-top2-interaction-in-the-presence-of-top2-targeting-agents
#9
Wan-Chen Huang, Chun-Ying Lee, Tao-Shih Hsieh
Topoisomerases play crucial roles in DNA replication, transcription, and recombination. For instance, topoisomerase II (Top2) is critically important for resolving DNA tangles during cell division, and as such, it is a broad anticancer drug target. Top2 regulates DNA topology by transiently breaking one double stranded DNA molecule (cleavage), allowing a second double strand to pass through the opened DNA gate (opening), and then closing the gate by rejoining the broken ends. Drugs that modulate Top2 catalysis may therefore affect enzymatic activity at several different steps...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630043/the-small-gtpases-k-ras-n-ras-and-h-ras-have-distinct-biochemical-properties-determined-by-allosteric-effects
#10
Christian W Johnson, Derion Reid, Jillian A Parker, Shores Salter, Ryan Knihtila, Petr Kuzmic, Carla Mattos
H-, K-, and N-Ras are small GTPases that are important in the control of cell proliferation, differentiation and survival, and their mutants occur frequently in human cancers. The G-domain, which catalyzes GTP hydrolysis and mediates downstream signaling, is 95% conserved between the Ras isoforms. Due to their very high sequence identity, biochemical studies done on H-Ras have been considered representative of all three Ras proteins. We show here that this is not a valid assumption. Using enzyme kinetic assays under identical conditions, we observed clear differences between the three isoforms in intrinsic catalysis of GTP by Ras in the absence and presence of the Ras-binding domain (RBD) of the C-Raf Kinase protein (Raf-RBD)...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630042/the-glutamate-cystine-antiporter-slc7a11-xct-enhances-cancer-cell-dependency-on-glucose-by-exporting-glutamate
#11
Pranavi Koppula, Yilei Zhang, Jiejun Shi, Wei Li, Boyi Gan
Cancer cells with specific genetic alterations may be highly dependent on certain nutrients for survival, which can inform therapeutic strategies to target these cancer-specific metabolic vulnerabilities. The glutamate/cystine antiporter solute carrier family 7 member 11 (SLC7A11, also called xCT) is overexpressed in several cancers. Contrasting the established pro-survival roles of SLC7A11 under other stress conditions, here we report an unexpected finding that SLC7A11 overexpression enhances cancer cell dependency on glucose and renders cancer cells more sensitive to glucose starvation-induced cell death, and conversely, that SLC7A11 deficiency by either knockdown or pharmacological inhibition promotes cancer cell survival upon glucose starvation...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630041/dysregulated-zn-2-homeostasis-impairs-cardiac-type-2-ryanodine-receptor-and-mitsugumin-23-functions-leading-to-sarcoplasmic-reticulum-ca-2-leakage
#12
Benedict Reilly-O'Donnell, Gavin B Robertson, Angela Karumbi, Connor McIntyre, Wojciech Bal, Miyuki Nishi, Hiroshi Takeshima, Alan J Stewart, Samantha J Pitt
Aberrant Zn2+-homeostasis is associated with dysregulated intracellular Ca2+ release resulting in chronic heart failure. In the failing heart, a small population of cardiac ryanodine receptors (RyR2) display sub-conductance state gating leading to Ca2+ leakage from sarcoplasmic reticulum (SR) stores, which impairs cardiac contractility. Previous evidence suggests contribution of RyR2-independent Ca2+ leakage through an uncharacterized mechanism. We sought to examine the role of Zn2+ in shaping intracellular Ca2+ release in cardiac muscle...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630040/endoplasmic-reticulum-associated-degradation-of-the-renal-potassium-channel-romk-leads-to-type-ii-bartter-syndrome
#13
Brighid M O'Donnell, Timothy D Mackie, Arohan R Subramanya, Jeffrey L Brodsky
Type II Bartter syndrome is caused by mutations in the Renal Outer Medullary Potassium (ROMK) channel but the molecular mechanisms underlying this disease are poorly defined. To rapidly screen for ROMK function, we developed a yeast expression system and discovered that yeast cells lacking endogenous potassium channels could be rescued by WT ROMK but not by ROMK proteins containing one of four Bartter mutations. We also found that the mutant proteins were significantly less stable than WT ROMK. However, their degradation was slowed in the presence of a proteasome inhibitor or when yeast cells contained mutations in the CDC48 or SSA1 gene, which is required for endoplasmic reticulum (ER)-associated degradation (ERAD)...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28630039/low-level-internalization-of-cystatin-e-m-affects-legumain-activity-and-migration-of-melanoma-cells
#14
Hanna Wallin, Jenny Apelqvist, Freddi Andersson, Ulf Ekstr Oumlm, Magnus Abrahamson
The ratio between proteases and their inhibitors is unbalanced in cancer. The cysteine protease inhibitor cystatin C is internalized by some cancer cells and affect cellular properties. Here we aimed to investigate if uptake of cystatin C and the related inhibitor cystatin E/M occur in melanoma cell lines and to evaluate to what extent the uptake affects the legumain activity that is typically increased in melanoma. First we studied the basic expression, secretion and intracellular content of all type 2 cystatins, as well as expression and activity of their possible target enzymes legumain and cathepsin B, in MDA-MB-435S, A375 and C8161 melanoma cells...
June 19, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28623234/a-ciliary-opsin-in-the-brain-of-a-marine-annelid-zooplankton-is-uv-sensitive-and-the-sensitivity-is-tuned-by-a-single-amino-acid-residue
#15
Hisao Tsukamoto, I-Shan Chen, Yoshihiro Kubo, Yuji Furutani
Ciliary opsins were classically thought to function only in vertebrates for vision, but they have been recently identified also in invertebrates for non-visual photoreception. Larvae of the annelid Platynereis dumerilii are used as a zooplankton model, and this zooplankton species possesses a "vertebrate-type" ciliary opsin (named c-opsin) in the brain. Platynereis c-opsin is suggested to relay light signals to melatonin production and circadian behaviors. Thus, the spectral and biochemical characteristics of this c-opsin would be directly related to non-visual photoreception in this zooplankton model...
June 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28623233/structural-and-functional-analyses-of-pyroglutamate-amyloid-%C3%AE-specific-antibodies-as-a-basis-for-alzheimer-immunotherapy
#16
Anke Piechotta, Christoph Parthier, Martin Kleinschmidt, Kathrin Gnoth, Thierry Pillot, Inge Lues, Hans-Ulrich Demuth, Stephan Schilling, Jens-Ulrich Rahfeld, Milton T Stubbs
Alzheimers disease is associated with deposition of the amyloidogenic peptide Aβ in the brain. Passive immunization using Aβ-specific antibodies has been demonstrated to reduce amyloid deposition both in vitro and in vivo. As N terminally truncated pyroglutamate (pE)-modified Aβ species (AβpE3) exhibit enhanced aggregation potential and propensity to form toxic oligomers, they represent particularly attractive targets for antibody therapy. Here we present three separate monoclonal antibodies that specifically recognize AβpE3 with affinities of 1-10 nM and inhibit AβpE3 fibril formation in vitro...
June 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28623232/the-ring-finger-and-pdz-domain-containing-protein-pdzrn3-controls-localization-of-the-mg-2-regulator-claudin-16-in-renal-tube-epithelial-cells
#17
Kana Marunaka, Chisa Furukawa, Naoko Fujii, Toru Kimura, Takumi Furuta, Toshiyuki Matsunaga, Satoshi Endo, Hajime Hasegawa, Naohiko Anzai, Yasuhiro Yamazaki, Masahiko Yamaguchi, Akira Ikari
Ion exchange in the renal tubules is fundamental to the maintenance of physiological ion levels. Claudin-16 (CLDN16) regulates the paracellular reabsorption of Mg(2+) in the thick ascending limb of Henle's loop in the kidney, with dephosphorylation of CLDN16 increasing its intracellular distribution and decreasing paracellular Mg(2+) permeability. CLDN16 is located in the tight junctions, but the mechanism regulating its localization is unclear. Using yeast two-hybrid systems, we found that CLDN16 binds to PDZRN3, a protein containing both RING-finger and PDZ-domains...
June 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28623231/cry6aa1-a-bacillus-thuringiensis-nematocidal-and-insecticidal-toxin-forms-pores-in-planar-lipid-bilayers-at-extremely-low-concentrations-and-without-the-need-of-proteolytic-processing
#18
Eva Fortea, Vincent Lemieux, Léna Potvin, Vimbai Chikwana, Samantha Griffin, Thimothy Hey, David McCaskill, Kenneth Narva, Sek Yee Tan, Xiaoping Xu, Vincent Vachon, Jean-Louis Schwartz
Cry6Aa1 is a Bacillus thuringiensis (Bt) toxin active against nematodes and corn rootworm insects. Its 3-D molecular structure, which has been recently elucidated, is unique among those known for other Bt toxins. Typical three-domain Bt toxins permeabilise receptor-free planar lipid bilayers (PLBs) by forming pores at doses in the 1-50 μg/ml range. Solubilisation and proteolytic activation are necessary steps for PLB permeabilisation. In contrast to other Bt toxins, Cry6Aa1 formed pores in receptor-free bilayers at doses as low as 200 pg/ml in a wide range of pH (5...
June 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28623230/flexible-body-motions-of-calmodulin-and-the-farnesylated-hypervariable-region-yield-a-high-affinity-interaction-enabling-k-ras4b-membrane-extraction
#19
Hyunbum Jang, Avik Banerjee, Tanmay Chavan, Vadim Gaponenko, Ruth Nussinov
In calmodulin (CaM)-rich environments, oncogenic KRAS plays a critical role in adenocarcinomas by promoting PI3K/Akt signaling. We previously proposed that at elevated calcium levels in cancer, CaM recruits PI3Kα to the membrane and extracts K-Ras4B from the membrane, organizing a K-Ras4B/CaM/PI3Kα ternary complex. CaM can thereby replace a missing receptor tyrosine kinase signal to fully activate PI3Kα. Recent experimental data show that CaM selectively promotes K-Ras signaling, but not of N-Ras or H-Ras...
June 16, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28623229/zebrafish-znfl1s-control-the-expression-of-hoxb1b-in-the-posterior-neuroectoderm-by-acting-upstream-of-pou5f3-and-sall4
#20
Xiaohua Dong, Jingyun Li, Luqingqing He, Chun Gu, Wenshuang Jia, Yunyun Yue, Jun Li, Qinxin Zhang, Lele Chu, Qingshun Zhao
Transcription factors play crucial roles in patterning posterior neuroectoderm. Previously, zinc finger transcription factor znfl1 was reported to express in the posterior neuroectoderm of zebrafish embryos. However, its roles remain unknown. Here, we report that there are 13 copies of znfl1 in zebrafish genome and all the paralogues share highly identical protein sequences and cDNA sequences. When znfl1s are knocked down by using morpholino to inhibit their translations or dCas9-Eve to inhibit their transcriptions, the zebrafish gastrula displays reduced expression of hoxb1b, the maker gene for the posterior neuroectoderm...
June 16, 2017: Journal of Biological Chemistry
journal
journal
20327
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"