TY  - JOUR
AU  - Stevanović, Katarina S
AU  - Čepkenović, Bogdana
AU  - Križak, Strahinja
AU  - Pajić, Tanja
AU  - Todorović, Nataša
AU  - Živić, Miroslav Ž
PY  - 2023
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/6088
AB  - Ion channels are vital components of filamentous fungi signaling in communication with their environment. We exploited the ability of the apical region of growing sporangiophores of Phycomyces blakesleeanus to form membrane-enveloped cytoplasmic droplets (CDs), to examine ion currents in the filamentous fungi native plasma membrane. In hypoosmotic conditions, the dominant current in the CDs is ORIC, an osmotically activated, anionic, outwardly rectified, fast inactivating instantaneous current that we have previously characterized. Here, we examined the effect of ATP on ORIC. We show that CDs contain active mitochondria, and that respiration inhibition by azide accelerates ORIC inactivation. ATP, added intracellularly, reduced ORIC run-down and shifted the voltage dependence of inactivation toward depolarized potentials, in a manner that did not require hydrolysis. Notably, ATP led to slowing down of ORIC inactivation, as evidenced by an increased time constant of inactivation, τin, and slower decline of τin during prolonged recordings. Flavonoids (genistein and quercetin) had the effect on ORIC opposite to ATP, acting as current inhibitors, possibly by disrupting the stabilizing effect of ATP on ORIC. The integration of osmotic sensing with ATP dependence of the anionic current, typical of vertebrate cells, is described here for the first time in filamentous fungi.
PB  - Springer Nature
T2  - Scientific Reports
T1  - ATP modulation of osmotically activated anionic current in the membrane of Phycomyces blakesleeanus sporangiophore
IS  - 1
VL  - 13
DO  - 10.1038/s41598-023-39021-9
SP  - 11897
ER  - 

@article{
author = "Stevanović, Katarina S and Čepkenović, Bogdana and Križak, Strahinja and Pajić, Tanja and Todorović, Nataša and Živić, Miroslav Ž",
year = "2023",
abstract = "Ion channels are vital components of filamentous fungi signaling in communication with their environment. We exploited the ability of the apical region of growing sporangiophores of Phycomyces blakesleeanus to form membrane-enveloped cytoplasmic droplets (CDs), to examine ion currents in the filamentous fungi native plasma membrane. In hypoosmotic conditions, the dominant current in the CDs is ORIC, an osmotically activated, anionic, outwardly rectified, fast inactivating instantaneous current that we have previously characterized. Here, we examined the effect of ATP on ORIC. We show that CDs contain active mitochondria, and that respiration inhibition by azide accelerates ORIC inactivation. ATP, added intracellularly, reduced ORIC run-down and shifted the voltage dependence of inactivation toward depolarized potentials, in a manner that did not require hydrolysis. Notably, ATP led to slowing down of ORIC inactivation, as evidenced by an increased time constant of inactivation, τin, and slower decline of τin during prolonged recordings. Flavonoids (genistein and quercetin) had the effect on ORIC opposite to ATP, acting as current inhibitors, possibly by disrupting the stabilizing effect of ATP on ORIC. The integration of osmotic sensing with ATP dependence of the anionic current, typical of vertebrate cells, is described here for the first time in filamentous fungi.",
publisher = "Springer Nature",
journal = "Scientific Reports",
title = "ATP modulation of osmotically activated anionic current in the membrane of Phycomyces blakesleeanus sporangiophore",
number = "1",
volume = "13",
doi = "10.1038/s41598-023-39021-9",
pages = "11897"
}

Stevanović, K. S., Čepkenović, B., Križak, S., Pajić, T., Todorović, N.,& Živić, M. Ž.. (2023). ATP modulation of osmotically activated anionic current in the membrane of Phycomyces blakesleeanus sporangiophore. in Scientific Reports
Springer Nature., 13(1), 11897.
https://doi.org/10.1038/s41598-023-39021-9

Stevanović KS, Čepkenović B, Križak S, Pajić T, Todorović N, Živić MŽ. ATP modulation of osmotically activated anionic current in the membrane of Phycomyces blakesleeanus sporangiophore. in Scientific Reports. 2023;13(1):11897.
doi:10.1038/s41598-023-39021-9 .

Stevanović, Katarina S, Čepkenović, Bogdana, Križak, Strahinja, Pajić, Tanja, Todorović, Nataša, Živić, Miroslav Ž, "ATP modulation of osmotically activated anionic current in the membrane of Phycomyces blakesleeanus sporangiophore" in Scientific Reports, 13, no. 1 (2023):11897,
https://doi.org/10.1038/s41598-023-39021-9 . .

TY  - JOUR
AU  - Stevanović, Katarina
AU  - Čepkenović, Bogdana
AU  - Križak, Strahinja
AU  - Živić, Miroslav
AU  - Todorović, Nataša
PY  - 2023
UR  - http://radar.ibiss.bg.ac.rs/handle/123456789/5978
AB  - Studies of ion currents in filamentous fungi are a prerequisite for forming a complete
understanding of their physiology. Cytoplasmic droplets (CDs), obtained from sporangiophores of
Phycomyces blakesleeanus, are a model system that enables the characterization of ion currents in
the native membrane, including the currents mediated by the channels not yet molecularly identified.
Osmotically activated anionic current with outward rectification (ORIC) is a dominant current in
the membrane of cytoplasmic droplets under the conditions of hypoosmotic stimulation. We have
previously reported remarkable functional similarities of ORIC with the vertebrate volume regulated
anionic current (VRAC), such as dose-dependent activation by osmotic difference, ion selectivity
sequence, and time and voltage dependent profile of the current. Using the patch clamp method on
the CD membrane, we further resolve VRAC-like ORIC characteristics in this paper. We examine
the inhibition by extracellular ATP and carbenoxolone, the permeation of glutamate in presence of
chloride, selectivity for nitrates, and activation by GTP, and we show its single channel behavior
in excised membrane. We propose that ORIC is a functional counterpart of vertebrate VRAC in
filamentous fungi, possibly with a similar essential role in anion efflux during cell volume regulation.
PB  - Basel: MDPI
T2  - Journal of Fungi
T1  - Osmotically activated anion current of Phycomyces blakesleeanus-filamentous fungi counterpart to vertebrate volume regulated anion current
IS  - 6
VL  - 9
DO  - 10.3390/jof9060637
SP  - 637
ER  - 

@article{
author = "Stevanović, Katarina and Čepkenović, Bogdana and Križak, Strahinja and Živić, Miroslav and Todorović, Nataša",
year = "2023",
abstract = "Studies of ion currents in filamentous fungi are a prerequisite for forming a complete
understanding of their physiology. Cytoplasmic droplets (CDs), obtained from sporangiophores of
Phycomyces blakesleeanus, are a model system that enables the characterization of ion currents in
the native membrane, including the currents mediated by the channels not yet molecularly identified.
Osmotically activated anionic current with outward rectification (ORIC) is a dominant current in
the membrane of cytoplasmic droplets under the conditions of hypoosmotic stimulation. We have
previously reported remarkable functional similarities of ORIC with the vertebrate volume regulated
anionic current (VRAC), such as dose-dependent activation by osmotic difference, ion selectivity
sequence, and time and voltage dependent profile of the current. Using the patch clamp method on
the CD membrane, we further resolve VRAC-like ORIC characteristics in this paper. We examine
the inhibition by extracellular ATP and carbenoxolone, the permeation of glutamate in presence of
chloride, selectivity for nitrates, and activation by GTP, and we show its single channel behavior
in excised membrane. We propose that ORIC is a functional counterpart of vertebrate VRAC in
filamentous fungi, possibly with a similar essential role in anion efflux during cell volume regulation.",
publisher = "Basel: MDPI",
journal = "Journal of Fungi",
title = "Osmotically activated anion current of Phycomyces blakesleeanus-filamentous fungi counterpart to vertebrate volume regulated anion current",
number = "6",
volume = "9",
doi = "10.3390/jof9060637",
pages = "637"
}

Stevanović, K., Čepkenović, B., Križak, S., Živić, M.,& Todorović, N.. (2023). Osmotically activated anion current of Phycomyces blakesleeanus-filamentous fungi counterpart to vertebrate volume regulated anion current. in Journal of Fungi
Basel: MDPI., 9(6), 637.
https://doi.org/10.3390/jof9060637

Stevanović K, Čepkenović B, Križak S, Živić M, Todorović N. Osmotically activated anion current of Phycomyces blakesleeanus-filamentous fungi counterpart to vertebrate volume regulated anion current. in Journal of Fungi. 2023;9(6):637.
doi:10.3390/jof9060637 .

Stevanović, Katarina, Čepkenović, Bogdana, Križak, Strahinja, Živić, Miroslav, Todorović, Nataša, "Osmotically activated anion current of Phycomyces blakesleeanus-filamentous fungi counterpart to vertebrate volume regulated anion current" in Journal of Fungi, 9, no. 6 (2023):637,
https://doi.org/10.3390/jof9060637 . .