Article
Physiology
Guanxing Chen, Qin Li, Timothy I. Webb, Mark A. Hollywood, Jiusheng Yan
Summary: This study identifies positively charged peptides as modulators of BK channels, and reveals a role for the Ca2+-bowl site and the C-terminal positively charged regions of auxiliary gamma subunits in BK channel modulation. The positively charged peptides and the cationic HIV-1 Tat peptide can shift the voltage-gating of BK channels towards hyperpolarization. The modulatory effects of the synthetic peptides are reduced in the presence of Ca2+ and can be abolished by charge neutralization of the Ca2+-bowl site and high ionic strength.
JOURNAL OF GENERAL PHYSIOLOGY
(2023)
Article
Biochemistry & Molecular Biology
Guanxing Chen, Qin Li, Jiusheng Yan
Summary: In this study, the function of the LRR domains in modulation of BK channels by auxiliary gamma subunits was investigated. The results showed that the LRR domain is essential for the all-or-none phenomenon of BK channel modulation by the gamma 1 subunit. Furthermore, N-glycosylation plays a crucial role in the modulation of BK channels by the gamma subunits.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2022)
Article
Chemistry, Multidisciplinary
Nadja Hellmann, Dirk Schneider
Summary: This study investigates the dimerization propensity of transmembrane helices in the cytoplasmic membrane of E. coli. The results suggest that the oligomerization propensity of a transmembrane helix can be influenced not only by sequence specificity but also by hydrophobic mismatch between the helix and the E. coli membrane.
FRONTIERS IN CHEMISTRY
(2022)
Article
Multidisciplinary Sciences
Adam Feher, Zoltan Petho, Tibor G. Szanto, Almos Klekner, Gabor Tajti, Gyula Batta, Tibor Hortobagyi, Zoltan Varga, Albrecht Schwab, Gyorgy Panyi
Summary: This study found functional expression of K(Ca)1.1/β3 complex in glioblastoma cells, suggesting its potential diagnostic and therapeutic role in glioblastoma.
SCIENTIFIC REPORTS
(2022)
Review
Neurosciences
Vivian Gonzalez-Perez, Yu Zhou, Matthew A. Ciorba, Christopher J. Lingle
Summary: Large conductance K+ channels (BK channels), regulated by cell-specific subunits, play important roles in various cellular and physiological functions. LRRC26, a member of the LRRC family, not only functions as a tumor suppressor, but is also highly expressed in secretory epithelial cells and regulates BK channels to maintain normal secretory function. LRRC26 may also be important in other organs like airways, female reproductive tract, and mammary gland. Future research should focus on understanding the mechanisms of LRRC-dependent pathologies and their impact on gene regulation.
JOURNAL OF PHYSIOLOGY-LONDON
(2022)
Article
Multidisciplinary Sciences
Kenichiro Sadamitsu, Leona Shigemitsu, Marina Suzuki, Daishi Ito, Makoto Kashima, Hiromi Hirata
Summary: The study cloned the genes of zebrafish GABA(A) receptor subunits, investigated their expression patterns and electrophysiological properties, revealing that the functional characteristics of zebrafish GABA(A) receptors are conserved among vertebrates.
SCIENTIFIC REPORTS
(2021)
Article
Biochemistry & Molecular Biology
Anna N. Bukiya, M. Dennis Leo, Jonathan H. Jaggar, Alex M. Dopico
Summary: The activation of BK currents by CLR enrichment requires a prolonged cellular process and is determined by a trafficking-dependent increase in membrane levels of KCNMB1 subunits.
JOURNAL OF BIOLOGICAL CHEMISTRY
(2021)
Article
Biology
Aleksandra Garifulina, Theres Friesacher, Marco Stadler, Eva-Maria Zangerl-Plessl, Margot Ernst, Anna Stary-Weinzinger, Anita Willam, Steffen Hering
Summary: The beta subunits of GABAA receptors can form homomeric proton-gated ion channels, which have not been previously described. The activation of these channels is mediated by a single histidine residue, and it is associated with chloride and bicarbonate currents in neuronal and non-neuronal tissues, suggesting a physiological role and potential as a drug target.
COMMUNICATIONS BIOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Qian Ju, Jieru Wang, Hualu Zhou, Dingkui Qin, Xiaoyan Hu, David Julian McClements, Guangzhong Luan
Summary: Understanding the impact of pH and ionic strength on the physicochemical and structural properties of soy proteins at subunit level is essential for design and fabrication of plant-based foods. The study shows that soybean beta-conglycinin and its subunits are sensitive to pH and ionic strength, exhibiting different stability and aggregation states under different conditions. The highly hydrophilic extension region of the alpha alpha '-subunits and N-linked glycans play important roles in determining the stability and conformation of beta-conglycinin dispersions.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Chemistry, Applied
Chang Wu, Qian Ju, Yanqiu Yuan, Jieru Wang, Fengyan Wu, Yayun Hu, Guangzhong Luan
Summary: In the soybean beta-conglycinin system, the subunit composition plays an important role in its emulsification properties. When the ratio of alpha alpha'-subunit to beta-subunit is 5:5, the subunit aqueous dispersion system exhibits optimal emulsification stability and emulsification activity. The formation of a protein network structure between alpha alpha'-subunit and beta-subunit provides a structural basis for its emulsification. Hydrophobic interactions primarily drive the adsorption and emulsion formation between subunits. The emulsifying mechanism involves establishing a protein network structure, developing an emulsion interface layer, and forming an emulsion gel network structure.
FOOD HYDROCOLLOIDS
(2024)
Article
Multidisciplinary Sciences
Alexander Kolesnikov, Elena Lobysheva, Jaya P. Gnana-Prakasam, Vladimir J. Kefalov, Oleg G. Kisselev
Summary: This study demonstrates that Gγ subunits have functional activity and can be swapped in supporting rod phototransduction, but replacing retina-specific Gγ isoforms affects rods' ability to adapt to background light.
Article
Biochemistry & Molecular Biology
Zhaoli Yu, Zihan Wu, Ye Li, Qiang Hao, Xiaofeng Cao, Gregor M. Blaha, Jinzhong Lin, Guoliang Lu
Summary: Two types of glycyl-tRNA synthetase (GlyRS) have been identified, alpha(2) and alpha(2)beta(2) GlyRSs. While the mechanisms for alpha(2) GlyRSs are well understood, little is known about the mechanisms for alpha(2)beta(2)/(alpha beta)(2) GlyRSs. This study presents the structures of the (alpha beta)(2) GlyRS from Oryza sativa chloroplast, revealing a complex mechanism of tRNA selection and access to the active site.
NUCLEIC ACIDS RESEARCH
(2023)
Article
Multidisciplinary Sciences
Guohui Zhang, Xianjin Xu, Zhiguang Jia, Yanyan Geng, Hongwu Liang, Jingyi Shi, Martina Marras, Carlota Abella, Karl L. Magleby, Jonathan R. Silva, Jianhan Chen, Xiaoqin Zou, Jianmin Cui
Summary: Researchers have discovered a compound, BC5, that interacts with the CTD-VSD interface and specifically modulates the Ca2+ dependent activation mechanism. BC5 can activate the channel in the absence of Ca2+ binding, but Ca2+ binding inhibits BC5 effects. This study reveals the importance of the CTD-VSD interaction in the Ca2+ activation mechanism and provides insights for allosteric agonists to modulate BK channel activation.
NATURE COMMUNICATIONS
(2022)
Article
Multidisciplinary Sciences
Kelsey C. North, Andrew A. Shaw, Anna N. Bukiya, Alex M. Dopico
Summary: Progesterone activates BK channels in mouse cerebrovascular myocytes by binding to the regulatory subunits, with a high-affinity site enabling steroid binding at a low-affinity site to activate the channel. Mutation of the high-affinity site weakens channel activation by progesterone, indicating its permissive role.
NATURE COMMUNICATIONS
(2023)
Article
Pharmacology & Pharmacy
Kelsey C. North, Man Zhang, Aditya K. Singh, Dasha Zaytseva, Alexandria Slayden, Anna N. Bukiya, Alex M. Dopico
Summary: This study reveals that inhibition of calcium/voltage-gated BK channels by membrane cholesterol requires physiological levels of internal calcium (Ca2+) and is selectively linked to high-affinity Ca2+-sensing sites located in the cytosolic tail domain.
MOLECULAR PHARMACOLOGY
(2022)
Article
Biochemistry & Molecular Biology
Maria J. Guerra, Arlek M. Gonzalez-Jamett, Ximena Baez-Matus, Nieves Navarro-Quezada, Agustin D. Martinez, Alan Neely, Ana M. Cardenas
JOURNAL OF NEUROCHEMISTRY
(2019)
Article
Biochemistry & Molecular Biology
Eliseo A. Eugenin, Silvana Valdebenito, Anna Maria Gorska, Agustin D. Martinez, Marcela Bitran, Juan C. Saez
JOURNAL OF NEUROCHEMISTRY
(2019)
Article
Neurosciences
Cristina Pinto, Danilo B. Medinas, Francisco Fuentes-Villalobos, Jaime Maripillan, Ariel F. Castro, Agustin D. Martinez, Nelson Osses, Claudio Hetz, Juan P. Henriquez
NEUROBIOLOGY OF DISEASE
(2019)
Article
Immunology
Paloma A. Harcha, Ximena Lopez, Pablo J. Saez, Paola Fernandez, Ivan Barria, Agustin D. Martinez, Juan C. Saez
FRONTIERS IN IMMUNOLOGY
(2019)
Correction
Physiology
Vania A. Figueroa, Oscar Jara, Carolina A. Oliva, Marcelo Ezquer, Fernando Ezquer, Mauricio A. Retamal, Agustin D. Martinez, Guillermo A. Altenberg, Anibal A. Vargas
FRONTIERS IN PHYSIOLOGY
(2020)
Article
Physiology
Vania A. Figueroa, Oscar Jara, Carolina A. Oliva, Marcelo Ezquer, Fernando Ezquer, Mauricio A. Retamal, Agustin D. Martinez, Guillermo A. Altenberg, Anibal A. Vargas
FRONTIERS IN PHYSIOLOGY
(2020)
Article
Biochemistry & Molecular Biology
Maria C. Maldifassi, Fanny Momboisse, Maria J. Guerra, Alex H. Vielma, Jaime Maripillan, Ximena Baez-Matus, Carolina Flores-Munoz, Barbara Cadiz, Oliver Schmachtenberg, Agustin D. Martinez, Ana M. Cardenas
Summary: This study proposes a novel mechanism for Panx1 channel activation through functional interactions with the highly calcium-permeable alpha 7 nicotinic acetylcholine receptor (nAChR), and demonstrates the physiological relevance of Panx1 channels and P2X7 receptors in neurosecretion.
JOURNAL OF NEUROCHEMISTRY
(2021)
Article
Biochemistry & Molecular Biology
Ximena Lopez, Rosalba Escamilla, Paola Fernandez, Yorley Duarte, Fernando Gonzalez-Nilo, Nicolas Palacios-Prado, Agustin D. Martinez, Juan C. Saez
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2020)
Article
Biochemistry & Molecular Biology
Carolina Flores-Munoz, Jaime Maripillan, Jacqueline Vasquez-Navarrete, Joel Novoa-Molina, Ricardo Ceriani, Helmuth A. Sanchez, Ana C. Abbott, Caroline Weinstein-Oppenheimer, Donald I. Brown, Ana Maria Cardenas, Isaac E. Garcia, Agustin D. Martinez
Summary: The study revealed that Panx1 channels play a crucial role in human dermal fibroblast migration during wound healing, with their absence or inhibition accelerating cell migration and promoting actin redistribution. This occurs through the release of ATP to the extracellular space and activation of the purinergic receptor P2X7.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Review
Biochemistry & Molecular Biology
Jorge Gonzalez-Casanova, Oliver Schmachtenberg, Agustin D. Martinez, Helmuth A. Sanchez, Paloma A. Harcha, Diana Rojas-Gomez
Summary: Diabetic retinopathy is a major cause of vision loss in the working age population, characterized by progressive deterioration of retinal microvasculature due to long-term metabolic changes. Gap junction channels and connexin hemichannels have been identified as key factors in the pathogenesis of diabetic retinopathy. Understanding the physiological impact of diabetes on these channels and their role in the disease process could lead to the development of novel pharmacological interventions.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2021)
Article
Multidisciplinary Sciences
Ximena Lopez, Nicolas Palacios-Prado, Juan Guiza, Rosalba Escamilla, Paola Fernandez, Jose L. Vega, Maximiliano Rojas, Valeria Marquez-Miranda, Eduardo Chamorro, Ana M. Cardenas, Maria Constanza Maldifassi, Agustin D. Martinez, Yorley Duarte, Fernando D. Gonzalez-Nilo, Juan C. Saez
Summary: This study identified S394 as a potential phosphorylation site for CaMKII in Panx1 channels, showing that phosphorylation at this site may activate Panx1 channels, allowing for ATP release and DAPI uptake. The results suggest a mechanism for Panx1 activation in response to increased cytoplasmic calcium signals without cleavage of the C-terminal domain.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2021)
Review
Neurosciences
Sofia Waissbluth, Juan Cristobal Maass, Helmuth A. Sanchez, Agustin D. Martinez
Summary: This article discusses the effects of cisplatin on the inner ear and its potential mechanisms for causing hearing loss, focusing on the role of transporters and gap junctions expressed by supporting cells in this process.
FRONTIERS IN NEUROSCIENCE
(2022)
Article
Biochemistry & Molecular Biology
Lucas Bayones, Maria Jose Guerra-Fernandez, Fernando Hinostroza, Ximena Baez-Matus, Jacqueline Vasquez-Navarrete, Luciana Gallo, Sergio Parra, Agustin D. Martinez, Arlek Gonzalez-Jamett, Fernando D. Marengo, Ana M. Cardenas
Summary: Gain-of-function mutations of dynamin-2 result in centronuclear myopathy by impairing exocytosis, disrupting actin filament formation and impacting the plasmalemma expression of functional proteins in skeletal muscle cells.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2022)
Article
Cell Biology
Carolina Flores-Munoz, Francisca Garcia-Rojas, Miguel A. Perez, Odra Santander, Elena Mery, Stefany Ordenes, Javiera Illanes-Gonzalez, Daniela Lopez-Espindola, Arlek M. Gonzalez-Jamett, Marco Fuenzalida, Agustin D. Martinez, Alvaro O. Ardiles
Summary: Enhanced activity and overexpression of Pannexin 1 (Panx1) channels contribute to neuronal pathologies. The absence of Panx1 in the adult brain promotes structural and functional modifications in hippocampal synapses, preserving spontaneous activity. These modifications are related to actin-cytoskeleton dynamics and Rho GTPases.
Article
Cell Biology
Ana C. Abbott, Isaac E. Garcia, Felipe Villanelo, Carolina Flores-Munoz, Ricardo Ceriani, Jaime Maripillan, Joel Novoa-Molina, Cindel Figueroa-Cares, Tomas Perez-Acle, Juan C. Saez, Helmuth A. Sanchez, Agustin D. Martinez
Summary: It has been demonstrated that a genetic mutation in the gap junction protein Connexin 26 (Cx26) can lead to hyperactivity and damage of hearing cells in the cochlea, resulting in syndromic deafness. The specific mutation Cx26S17F, when co-expressed with wild-type connexins like Cx30, forms hyperactive hemichannels in supporting cells of the organ of Corti. These hyperactive hemichannels are insensitive to blockers and ions, leading to abnormal calcium influx and cellular damage.
FRONTIERS IN CELL AND DEVELOPMENTAL BIOLOGY
(2023)