Review
Physiology
Himanshu Malhotra, Cassandra L. Barnes, Peter D. Calvert
Summary: Retinal photoreceptors are neurons that convert light into electrical signals for transmission to the brain. The functions of photoreceptors are divided into three specialized compartments- the outer segment, inner segment, and pre-synaptic terminal. Disruption of this compartmentalization can lead to devastating blinding diseases.
PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY
(2021)
Review
Cell Biology
Cassandra L. Barnes, Himanshu Malhotra, Peter D. Calvert
Summary: Primary cilia act as functional compartments within cells, enriching molecules involved in signal transduction and playing a crucial role in adaptation to environmental stimuli. Research into the molecular mechanisms of ciliary compartmentalization is ongoing, revealing both similarities and differences between primary cilia and sensory cilia. The evolution of photoreceptors into specialized neurons relying on highly specialized cilia for signaling changes in light intensity has driven unique mechanisms for protein and membrane compartmentalization.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2021)
Article
Multidisciplinary Sciences
Raphael S. Haider, Edda S. F. Matthees, Julia Drube, Mona Reichel, Ulrike Zabel, Asuka Inoue, Andy Chevigne, Cornelius Krasel, Xavier Deupi, Carsten Hoffmann
Summary: This study reveals that beta-arrestin1 and 2 exhibit different responses and distinct conformations when binding to the same GPCR, which are regulated by proximal and distal C-terminal phosphorylation.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Julien Bous, Aurelien Fouillen, Helene Orcel, Stefano Trapani, Xiaojing Cong, Simon Fontanel, Julie Saint-Paul, Josephine Lai-Kee-Him, Serge Urbach, Nathalie Sibille, Remy Sounier, Sebastien Granier, Bernard Mouillac, Patrick Bron
Summary: Recent structural studies have provided insights into the molecular mechanisms of GPCR-arrestin coupling, but it is unclear whether this process is conserved among different GPCRs. In this study, the cryo-electron microscopy active structure of the wild-type arginine-vasopressin V2 receptor (V2R) in complex with beta-arrestin1 was determined, revealing a unique arrangement of beta-arrestin1 and an interface involving all receptor intracellular loops. These findings suggest a significant structural variability among GPCR-arrestin signaling complexes.
Review
Biochemistry & Molecular Biology
Peter Thomas, Yefei Pang, Jan Kelder
Summary: Significant progress has been made in the understanding of membrane progesterone receptors (mPRs), including their nongenomic actions, ligand binding, intracellular signaling pathways, and functions in reproductive and nonreproductive tissues. Although belonging to the progestin adipoQ receptor (PAQR) family, the 3-D structures and structural characteristics of mPRs remain unknown. The mechanisms regulating mPR functions and trafficking to the cell surface have been overlooked, and this paper provides a summary of their structural aspects and potential mechanisms for further investigation.
Article
Chemistry, Multidisciplinary
Udeep Chawla, Suchithranga M. D. C. Perera, Steven D. E. Fried, Anna R. Eitel, Blake Mertz, Nipuna Weerasinghe, Michael C. Pitman, Andrey V. Struts, Michael F. Brown
Summary: Visual rhodopsin absorbs light and takes in approximately 80 water molecules to form a solvent-swollen active state, which is essential for activating the photoreceptor and is supported by molecular dynamics simulations. Force-based measurements show that the expansion of rhodopsin occurs through changes in cavity volumes and increased hydration in the active Meta II state. Furthermore, the binding and release of the C-terminal helix of transducin is coupled to hydration changes, potentially influencing visual signal amplification through a dynamic allosteric mechanism involving lipid and water interactions in the catalytic G-protein cycle.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2021)
Article
Cell Biology
Yuka Ochi, Hitomi Yamashita, Yumi Yamada, Takunori Satoh, Akiko K. Satoh
Summary: This study investigated the mechanisms of polarized transport in Drosophila photoreceptors and found that Strat plays a crucial role in this process, especially in the stable expression of Rab10 and Rab35.
MOLECULAR BIOLOGY OF THE CELL
(2022)
Article
Biochemistry & Molecular Biology
Yukiko Yasuoka, Yuichiro Izumi, Takashi Fukuyama, Hideki Inoue, Tomomi Oshima, Taiga Yamazaki, Takayuki Uematsu, Noritada Kobayashi, Yoshitaka Shimada, Yasushi Nagaba, Masashi Mukoyama, Yuichi Sato, Jeff M. Sands, Katsumasa Kawahara, Hiroshi Nonoguchi
Summary: The kidney is the main site of erythropoietin production in the body. Research has shown that angiotensin II can stimulate erythropoietin production in the kidney, regulating erythropoietin production through the renin-angiotensin-aldosterone system (RAS).
Review
Biochemistry & Molecular Biology
Kacper Zbieralski, Donata Wawrzycka
Summary: Alpha-arrestins are a conserved family of proteins that selectively identify membrane proteins for ubiquitination and degradation, playing a crucial role in maintaining membrane protein homeostasis and global cellular metabolisms. Although the functions and regulation mechanisms of alpha-arrestins are not fully understood, their roles in redox homeostasis regulation, innate immune response regulation, and tumor suppression have been characterized in animal models.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Genetics & Heredity
Andreas R. Janecke, Xiaoqin Liu, Ruediger Adam, Sumanth Punuru, Arne Viestenz, Valeria Strauss, Martin Laass, Elizabeth Sanchez, Roberto Adachi, Martha P. Schatz, Ujwala S. Saboo, Naveen Mittal, Klaus Rohrschneider, Johanna Escher, Anuradha Ganesh, Sana Al Zuhaibi, Fathiya Al Murshedi, Badr AlSaleem, Majid Alfadhel, Siham Al Sinani, Fowzan S. Alkuraya, Lukas A. Huber, Thomas Mueller, Ruth Heidelberger, Roger Janz
Summary: New STX3 variants have been found to be associated with a syndrome including congenital enteropathy and retinal dystrophy. These variants affect STX3 transcripts, leading to reduced numbers of photoreceptors and thinning of cell layers.
Article
Cell Biology
Aleksander Tworak, Alexander Kolesnikov, John D. Hong, Elliot H. Choi, Jennings C. Luu, Grazyna Palczewska, Zhiqian Dong, Dominik Lewandowski, Matthew J. Brooks, Laura Campello, Anand Swaroop, Philip D. Kiser, Vladimir J. Kefalov, Krzysztof Palczewski
Summary: Using a cell-specific gene reactivation approach, we investigated the kinetics of RGR-mediated recovery of photoreceptor responses. We found that both RPE and a specialized subset of Mueuroller glia contribute to scotopic and photopic function, and demonstrated the role of 11-cis-retinal in rapid visual pigment regeneration.
Article
Multidisciplinary Sciences
Timothy J. Hawkins, Michaela Kopischke, Patrick J. Duckney, Katarzyna Rybak, David A. Mentlak, Johan T. M. Kroon, Mai Thu Bui, A. Christine Richardson, Mary Casey, Agnieszka Alexander, Geert De Jaeger, Monika Kalde, Ian Moore, Yasin Dagdas, Patrick J. Hussey, Silke Robatzek
Summary: This study reveals that NET4A and NET4B members of the NET family play an essential role in the reorganization of guard cell actin during stomatal closure, mediating the molecular link between actin filaments and the tonoplast through interaction with RABG3b.
NATURE COMMUNICATIONS
(2023)
Article
Medicine, Research & Experimental
Daniel C. Bittel, Sen Chandra Sreetama, Goutam Chandra, Robin Ziegler, Kanneboyina Nagaraju, Jack H. Van der Meulen, Jyoti K. Jaiswal
Summary: Efficient sarcolemmal repair is crucial for muscle cell survival. This study presents a novel gene therapy approach for limb girdle muscular dystrophy 2B (LGMD2B) targeting reduced secretion of acid sphingomyelinase (ASM). Treatment with liver-specific adeno-associated virus (AAV) vector expressing human ASM (hASM) restored membrane repair capacity and improved muscle strength in patient cells and a mouse model. This non-muscle-targeted gene therapy could attenuate muscle degeneration and provide a potential treatment for LGMD2B.
JOURNAL OF CLINICAL INVESTIGATION
(2022)
Article
Neurosciences
Anna Bodzeta, Nicky Scheefhals, Harold D. MacGillavry
Summary: The various functions of glutamate in the brain are mediated by ionotropic and metabotropic glutamate receptors, which modulate synaptic transmission and plasticity. mGluRs play roles at both presynaptic and postsynaptic sites, acting as essential signal integrators that couple mechanisms of transmission and plasticity.
Article
Chemistry, Physical
Satoshi Yasuda, Tomoki Akiyama, Keiichi Kojima, Tetsuya Ueta, Tomohiko Hayashi, Satoshi Ogasawara, Satoru Nagatoishi, Kouhei Tsumoto, Naoki Kunishima, Yuki Sudo, Masahiro Kinoshita, Takeshi Murata
Summary: A methodology was developed to identify thermostabilizing mutations in a membrane protein, resulting in the construction of quadruple mutants with a new thermal stability record in a class of outward proton pumping rhodopsins.
JOURNAL OF PHYSICAL CHEMISTRY B
(2022)