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Pajić T, Stevanović K, Todorović NV, Krmpot AJ, Živić M, Savić-Šević S, Lević SM, Stanić M, Pantelić D, Jelenković B, Rabasović MD. In vivo femtosecond laser nanosurgery of the cell wall enabling patch-clamp measurements on filamentous fungi. MICROSYSTEMS & NANOENGINEERING 2024; 10:47. [PMID: 38590818 PMCID: PMC10999429 DOI: 10.1038/s41378-024-00664-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 12/01/2023] [Accepted: 12/19/2023] [Indexed: 04/10/2024]
Abstract
Studying the membrane physiology of filamentous fungi is key to understanding their interactions with the environment and crucial for developing new therapeutic strategies for disease-causing pathogens. However, their plasma membrane has been inaccessible for a micron-sized patch-clamp pipette for pA current recordings due to the rigid chitinous cell wall. Here, we report the first femtosecond IR laser nanosurgery of the cell wall of the filamentous fungi, which enabled patch-clamp measurements on protoplasts released from hyphae. A reproducible and highly precise (diffraction-limited, submicron resolution) method for obtaining viable released protoplasts was developed. Protoplast release from the nanosurgery-generated incisions in the cell wall was achieved from different regions of the hyphae. The plasma membrane of the obtained protoplasts formed tight and high-resistance (GΩ) contacts with the recording pipette. The entire nanosurgical procedure followed by the patch-clamp technique could be completed in less than 1 hour. Compared to previous studies using heterologously expressed channels, this technique provides the opportunity to identify new ionic currents and to study the properties of the ion channels in the protoplasts of filamentous fungi in their native environment.
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Grants
- Ministarstvo Prosvete, Nauke i Tehnološkog Razvoja (Ministry of Education, Science and Technological Development of the Republic of Serbia)
- This work was supported by the Ministry of Science, Technological Development and Innovations, Republic of Serbia [contract number: 451-03-47/2023-01/200178]; The Project Advanced Biophysical Methods for Soil Targeted Fungi-Based Biocontrol Agents - BioPhysFUN [Grant number 4545] from Program DEVELOPMENT – Green program of cooperation between science and industry, Science Fund of the Republic of Serbia
- This work was supported by the Ministry of Science, Technological Development and Innovations, Republic of Serbia [contract number: 451-03-47/2023-01/200007]; The Project Advanced Biophysical Methods for Soil Targeted Fungi-Based Biocontrol Agents - BioPhysFUN [Grant number 4545] from Program DEVELOPMENT – Green program of cooperation between science and industry, Science Fund of the Republic of Serbia
- The Project Advanced Biophysical Methods for Soil Targeted Fungi-Based Biocontrol Agents - BioPhysFUN [Grant number 4545] from Program DEVELOPMENT – Green program of cooperation between science and industry, Science Fund of the Republic of Serbia; the Project HEMMAGINERO [Grant number 6066079] from Program PROMIS, Science Fund of the Republic of Serbia; and the Institute of Physics Belgrade, through the grant by the Ministry of Science, Technological Development and Innovations of the Republic of Serbia.
- The Institute of Physics Belgrade, through the grant by the Ministry of Science, Technological Development and Innovations of the Republic of Serbia
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Affiliation(s)
- Tanja Pajić
- Institute of Physiology and Biochemistry “Ivan Djaja”, Faculty of Biology, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
| | - Katarina Stevanović
- Institute of Physiology and Biochemistry “Ivan Djaja”, Faculty of Biology, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
| | - Nataša V. Todorović
- Institute for Biological Research “Siniša Stanković”, University of Belgrade, National Institute of the Republic of Serbia, Bulevar Despota Stefana 142, 11000 Belgrade, Serbia
| | - Aleksandar J. Krmpot
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Miroslav Živić
- Institute of Physiology and Biochemistry “Ivan Djaja”, Faculty of Biology, University of Belgrade, Studentski trg 16, 11158 Belgrade, Serbia
| | - Svetlana Savić-Šević
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Steva M. Lević
- University of Belgrade, Faculty of Agriculture, Nemanjina Street 6, 11080 Belgrade, Serbia
| | - Marina Stanić
- Institute for Multidisciplinary Research, University of Belgrade, Kneza Višeslava 1, 11030 Belgrade, Serbia
| | - Dejan Pantelić
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Brana Jelenković
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
| | - Mihailo D. Rabasović
- Institute of Physics Belgrade, University of Belgrade, National Institute of the Republic of Serbia, Pregrevica 118, 11080 Belgrade, Serbia
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Cerana R, Colombo R. K+and Cl−Conductance ofArabidopsis thalianaPlasma Membrane at Depolarized Voltages. ACTA ACUST UNITED AC 2014. [DOI: 10.1111/j.1438-8677.1992.tb00298.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Tavares B, Domingos P, Dias PN, Feijó JA, Bicho A. The essential role of anionic transport in plant cells: the pollen tube as a case study. JOURNAL OF EXPERIMENTAL BOTANY 2011; 62:2273-2298. [PMID: 21511914 DOI: 10.1093/jxb/err036] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Plasma membrane anion transporters play fundamental roles in plant cell biology, especially in stomatal closure and nutrition. Notwithstanding, a lot is still unknown about the specific function of these transporters, their specific localization, or molecular nature. Here the fundamental roles of anionic transport in plant cells are reviewed. Special attention will be paid to them in the control of pollen tube growth. Pollen tubes are extreme examples of cellular polarity as they grow exclusively in their apical extremity. Their unique cell biology has been extensively exploited for fundamental understanding of cellular growth and morphogenesis. Non-invasive methods have demonstrated that tube growth is governed by different ion fluxes, with different properties and distribution. Not much is known about the nature of the membrane transporters responsible for anionic transport and their regulation in the pollen tube. Recent data indicate the importance of chloride (Cl(-)) transfer across the plasma membrane for pollen germination and pollen tube growth. A general overview is presented of the well-known accumulated data in terms of biophysical and functional characterization, transcriptomics, and genomic description of pollen ionic transport, and the various controversies around the role of anionic fluxes during pollen tube germination, growth, and development. It is concluded that, like all other plant cells so far analysed, pollen tubes depend on anion fluxes for a number of fundamental homeostatic properties.
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Outwardly rectifying anionic channel from the plasma membrane of the fungus Phycomyces blakesleeanus. EUKARYOTIC CELL 2009; 8:1439-48. [PMID: 19592679 DOI: 10.1128/ec.00059-09] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the present report, by using a patch clamp technique, we provide, to our knowledge, the first detailed description of an anionic channel from filamentous fungi. The characterized channel, an outwardly rectifying anionic channel (ORAC), is the most prominent feature of the cell membrane of the fungus Phycomyces blakesleeanus in the absence of energizing substrates. The unitary conductance of the channel is 11.3 +/- 0.4 pS. It is characterized by a strong voltage dependence of the open-channel probability (zdelta; the gating charge is 2.1 +/- 0.1), and the channel is activated by depolarization. The values of the time constants for voltage-induced activation and deactivation of 28 +/- 3 ms for tau(a) and 39 +/- 9 ms for tau(d) show that the ORAC is characterized by fast activation/deactivation kinetics. The ORAC shows strong selectivity for anions over cations and weak selectivity among anions, with a selectivity sequence of I(-) >or= NO(3)(-) > Br(-) > Cl(-) > SO(4)(2-) = 4.8 > 4.4 > 2.2 > 1 > 0.55, which corresponds to Eisenman series 1. The channel is characterized by two open and two closed states, with dominant long open (tau(o2) = 35.0 +/- 3.9 ms) and long closed (tau(c2) = 166 +/- 28 ms) states occupying 63% +/- 8% and 79% +/- 3% of total open and closed times, respectively. The ORAC is insensitive to anthracene-9-carboxylic acid (<200 microM), but 2 mM malate reversibly inhibits 59% +/- 12% of the channel activity. Based on the electrophysiological properties of the channel, we propose that the ORAC plays a role in anion accumulation and in membrane potential regulation through local membrane depolarization.
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Sutter JU, Campanoni P, Tyrrell M, Blatt MR. Selective mobility and sensitivity to SNAREs is exhibited by the Arabidopsis KAT1 K+ channel at the plasma membrane. THE PLANT CELL 2006; 18:935-54. [PMID: 16531497 PMCID: PMC1425843 DOI: 10.1105/tpc.105.038950] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2005] [Revised: 02/13/2006] [Accepted: 02/17/2006] [Indexed: 05/07/2023]
Abstract
Recent findings indicate that proteins in the SNARE superfamily are essential for cell signaling, in addition to facilitating vesicle traffic in plant cell homeostasis, growth, and development. We previously identified SNAREs SYP121/Syr1 from tobacco (Nicotiana tabacum) and the Arabidopsis thaliana homolog SYP121 associated with abscisic acid and drought stress. Disrupting tobacco SYP121 function by expressing a dominant-negative Sp2 fragment had severe effects on growth, development, and traffic to the plasma membrane, and it blocked K(+) and Cl(-) channel responses to abscisic acid in guard cells. These observations raise questions about SNARE control in exocytosis and endocytosis of ion channel proteins and their organization within the plane of the membrane. We have used a dual, in vivo tagging strategy with a photoactivatable green fluorescent protein and externally exposed hemagglutinin epitopes to monitor the distribution and trafficking dynamics of the KAT1 K(+) channel transiently expressed in tobacco leaves. KAT1 is localized to the plasma membrane within positionally stable microdomains of approximately 0.5 microm in diameter; delivery of the K(+) channel, but not of the PMA2 H(+)-ATPase, to the plasma membrane is suppressed by Sp2 fragments of tobacco and Arabidopsis SYP121, and Sp2 expression leads to profound changes in KAT1 distribution and mobility within the plane of the plasma membrane. These results offer direct evidence for SNARE-mediated traffic of the K(+) channel and a role in its distribution within subdomains of the plasma membrane, and they implicate a role for SNAREs in positional anchoring of the K(+) channel protein.
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Affiliation(s)
- Jens-Uwe Sutter
- Laboratory of Plant Physiology and Biophysics, Institute of Biomedical and Life Sciences-Plant Sciences, University of Glasgow, Glasgow G12 8QQ, UK
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Roberts SK. Plasma membrane anion channels in higher plants and their putative functions in roots. THE NEW PHYTOLOGIST 2006; 169:647-66. [PMID: 16441747 DOI: 10.1111/j.1469-8137.2006.01639.x] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
Recent years have seen considerable progress in identifying anion channel activities in higher plant cells. This review outlines the functional properties of plasma membrane anion channels in plant cells and discusses their likely roles in root function. Plant anion channels can be grouped according to their voltage dependence and kinetics: (1) depolarization-activated anion channels which mediate either anion efflux (R and S types) or anion influx (outwardly rectifying type); (2) hyperpolarization-activated anion channels which mediate anion efflux, and (3) anion channels activated by light or membrane stretch. These types of anion channel are apparent in root cells where they may function in anion homeostasis, membrane stabilization, osmoregulation, boron tolerance and regulation of passive salt loading into the xylem vessels. In addition, roots possess anion channels exhibiting unique properties which are consistent with them having specialized functions in root physiology. Most notable are the organic anion selective channels, which are regulated by extracellular Al3+ or the phosphate status of the plant. Finally, although the molecular identities of plant anion channels remain elusive, the diverse electrophysiological properties of plant anion channels suggest that large and diverse multigene families probably encode these channels.
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Affiliation(s)
- Stephen K Roberts
- Lancaster Environment Centre, Biology Department, Lancaster University, Lancaster LA1 4YQ, UK.
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Bregante M, Gambale F, LoSchiavo F. Ionic transport in the plasma membrane of carrot protoplasts from embryogenic cell-suspension cultures. FEBS Lett 1996; 380:97-102. [PMID: 8603756 DOI: 10.1016/0014-5793(96)00016-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Ionic transport properties of protoplasts obtained from embryogenic carrot suspension cells were studied by the patch-clamp technique. In the whole-cell configuration, carrot protoplasts presented macroscopic time-dependent outward currents, showing kinetics of activation which did not depend appreciably on the amplitude of the stimulus. Time- and voltage-dependent whole-cell inward rectifying currents as well as instantaneous non-selective currents were also observed. Both time-dependent inward and outward currents are carried by potassium ions. In a cell-attached configuration, two types of single-channel signals, displaying conductances of 10 and 17 pS, were observed; the instantaneous 10 pS channel was also present in outside-out excised patches.
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Affiliation(s)
- M Bregante
- Istituto di Cibernetica e Biofisica, CNR, Genova, Italy
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Ketchum KA, Slayman CW. Isolation of an ion channel gene from Arabidopsis thaliana using the H5 signature sequence from voltage-dependent K+ channels. FEBS Lett 1996; 378:19-26. [PMID: 8549795 DOI: 10.1016/0014-5793(95)01417-9] [Citation(s) in RCA: 73] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
A degenerate oligonucleotide corresponding to the K+ channel signature sequence (TMTTVGYGD) was used to isolate the genomic and cDNA forms of a new channel gene, AKT3, from Arabidopsis thaliana. The deduced protein sequence has a predicted membrane topography similar to Shaker-like K+ channels. Three distinct modules comprise the carboxyl-terminal half: a nucleotide-binding motif, an ankyrin repeat domain, and a polyglutamate track. Xenopus oocytes injected with cRNA exhibited an inward-rectifying K+ current, demonstrating that the AKT3 polypeptide is a functional transport protein. Two other Arabidopsis K+ transporters (AKT1 and KAT1) share 60% homology with AKT3; together these proteins constitute a family of plant inward-rectifying K+ channels.
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Affiliation(s)
- K A Ketchum
- Department of Genetics, Yale University School of Medicine, New Haven, CT 06510, USA
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Vogelzang SA, Prins HB. Kinetic analysis of two simultaneously activated K+ currents in root cell protoplasts of Plantago media L. J Membr Biol 1995; 146:59-71. [PMID: 7563037 DOI: 10.1007/bf00232680] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Two different, simultaneously activated outward rectifying K+ currents were analyzed in the plasmalemma of root cortex protoplasts of Plantago media. Their gating is dependent on the diffusion potential for K+(EK). The threshold potential was more negative than EK allowing small inward currents at potentials below EK thereby keeping cells with little pump activity in the K state (Vogelzang & Prins, 1994). Time and voltage dependence of the outward rectifying K+ currents have been analyzed with Hodgkin-Huxley-like (HH) models. Dynamic responses of whole cell currents to pulse potentials were analyzed with two voltage dependent functions, the Boltzmann distribution for open probability per gate and the transition rate towards the open state (alpha). The transition rate in the opposite direction (beta), was calculated from alpha and the Boltzmann distribution. These functions were used for an integral analysis of activation and deactivation currents measured over a range of pulse potentials. Both whole cell and single channel data were used for the determination of the number of closed and open states. The effects of single channel flickering on time response and amplitude of tail currents were added to the model. The dominant K+ channel present in the plasmalemma of P. media has a characteristic nonlinear single channel I-V curve reducing the amplitude of whole cell currents at positive potentials. To compensate for this nonlinearity, a four state translocator model was added to the whole cell open probability model. The analysis presented here provides a general basis for the study and comparison of K+ channel kinetics in plant protoplasts.
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Affiliation(s)
- S A Vogelzang
- ECOTRANS, Dept of Plant Biology, University of Groningen, The Netherlands
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Hedrich R, Becker D. Green circuits--the potential of plant specific ion channels. PLANT MOLECULAR BIOLOGY 1994; 26:1637-1650. [PMID: 7532027 DOI: 10.1007/bf00016494] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Affiliation(s)
- R Hedrich
- Institut für Biophysik, Hannover, Germany
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12
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Bouteau F, Perino C, Cornel D, Rona J. Sugar absorption and potassium channels in protoplasts of Hevea brasiliensis laticiferous vessels. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/0302-4598(93)80009-j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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13
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Stoeckel H, Takeda K. Plasmalemmal, voltage-dependent ionic currents from excitable pulvinar motor cells of Mimosa pudica. J Membr Biol 1993; 131:179-92. [PMID: 7684082 DOI: 10.1007/bf02260107] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Plasmalemmal ionic currents from excitable motor cells of the primary pulvinus of Mimosa pudica were investigated by patch-clamp techniques. In almost all of the enzymatically isolated protoplasts, a delayed rectifier potassium current was activated by depolarization, while no currents were detected upon hyperpolarization. This sustained outward current was reversibly blocked by Ba and TEA and serves to repolarize the membrane potential. Outward single channel currents that very likely underly the macroscopic outward potassium current had an elementary conductance of approximately 20 pS. In addition, in a few protoplasts held at hyperpolarized potentials, depolarization-activated transient inward currents were observed, and under current clamp, action potential-like responses were triggered by depolarizing current injections or by mechanical perturbations. The activation characteristics of both inward currents and spikes showed striking similarities compared to those of action potentials in situ.
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Affiliation(s)
- H Stoeckel
- Institut de Biologie Moléculaire des Plantes-CNRS UPR406, Strasbourg, France
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Bulychev AA, Antonov VF, Schevchenko EV. Patch-clamp studies of light-induced currents across the thylakoid membrane of isolated chloroplasts. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 1992. [DOI: 10.1016/0005-2728(92)90182-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Terry BR, Tyerman SD, Findlay GP. Ion channels in the plasma membrane of Amaranthus protoplasts: one cation and one anion channel dominate the conductance. J Membr Biol 1991; 121:223-36. [PMID: 1713975 DOI: 10.1007/bf01951556] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
This report details preliminary findings for ion channels in the plasma membrane of protoplasts derived from the cotyledons of Amaranthus seedlings. The conductance properties of the membrane can be described almost entirely by the behavior of two types of ion channel observed as single channels in attached and detached patches. The first is a cation-selective outward rectifier, and the second a multistate anion-selective channel which, under physiological conditions, acts as an inward rectifier. The cation channel has unit conductance of approx. 30 pS (symmetrical 100 K+) and relative permeability sequence K+ greater than Na+ much greater than Cl- (1:0.16:0.03): whole-cell currents activate in a time-dependent manner, and both activation and deactivation kinetics are voltage dependent. The anion channel opens for hyperpolarized membrane potentials, has a full-level conductance of approx. 200 pS and multiple subconductance states. The number of subconductances does not appear to be fixed. When activated the channel is open for long periods, though shuts if the membrane potential (Vm) is depolarized; at millimolar levels of [Ca2+]cyt this voltage dependency disappears. Inward current attributable to the anion channel is not observed in whole-cell recordings when MgATP (2 mM) is present in the intracellular solution. By contrast the channel is active in most detached patches, whether MgATP is present or not on the cytoplasmic face of the membrane. The anion channel has a significant permeability to cations, the sequence being NO3- greater than Cl- greater than K+ greater than Aspartate (2.04:1:0.18 to 0.09:0.04). The relative permeability for K+ decreased at progressively lower conductance states. In the absence of permeant anions this channel could be mistaken for a cation inward rectifier. The anion and cation channels could serve to clamp Vm at a preferred value in the face of events which would otherwise perturb Vm.
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Affiliation(s)
- B R Terry
- School of Biological Sciences, Flinders University of South Australia, Bedford Park
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