Heliorhodopsin binds and regulates glutamine synthetase activity.
Photoreceptors are light-sensitive proteins found in various organisms that respond to light and relay signals into the cells. Heliorhodopsin, a retinal-binding membrane protein, has been recently discovered, however its function remains unknown. Herein, we investigated the relationship between Acti...
| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
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Public Library of Science (PLoS)
2022-10-01
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| Series: | PLoS Biology |
| Online Access: | https://doi.org/10.1371/journal.pbio.3001817 |
| _version_ | 1811326290606686208 |
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| author | Shin-Gyu Cho Myungchul Song Kimleng Chuon Jin-Gon Shim Seanghun Meas Kwang-Hwan Jung |
| author_facet | Shin-Gyu Cho Myungchul Song Kimleng Chuon Jin-Gon Shim Seanghun Meas Kwang-Hwan Jung |
| author_sort | Shin-Gyu Cho |
| collection | DOAJ |
| description | Photoreceptors are light-sensitive proteins found in various organisms that respond to light and relay signals into the cells. Heliorhodopsin, a retinal-binding membrane protein, has been recently discovered, however its function remains unknown. Herein, we investigated the relationship between Actinobacteria bacterium IMCC26103 heliorhodopsin (AbHeR) and an adjacent glutamine synthetase (AbGS) in the same operon. We demonstrate that AbHeR binds to AbGS and regulates AbGS activity. More specifically, the dissociation constant (Kd) value of the binding between AbHeR and AbGS is 6.06 μM. Moreover, the absence of positively charged residues within the intracellular loop of AbHeR impacted Kd value as they serve as critical binding sites for AbGS. We also confirm that AbHeR up-regulates the biosynthetic enzyme activity of AbGS both in vitro and in vivo in the presence of light. GS is a key enzyme involved in nitrogen assimilation that catalyzes the conversion of glutamate and ammonia to glutamine. Hence, the interaction between AbHeR and AbGS may be critical for nitrogen assimilation in Actinobacteria bacterium IMCC26103 as it survives in low-nutrient environments. Overall, the findings of our study describe, for the first time, to the best of our knowledge, a novel function of heliorhodopsin as a regulatory rhodopsin with the capacity to bind and regulate enzyme activity required for nitrogen assimilation. |
| first_indexed | 2024-04-13T14:47:23Z |
| format | Article |
| id | doaj.art-e6bacb2f16ec46dbba6ef35f8839bb25 |
| institution | Directory Open Access Journal |
| issn | 1544-9173 1545-7885 |
| language | English |
| last_indexed | 2024-04-13T14:47:23Z |
| publishDate | 2022-10-01 |
| publisher | Public Library of Science (PLoS) |
| record_format | Article |
| series | PLoS Biology |
| spelling | doaj.art-e6bacb2f16ec46dbba6ef35f8839bb252022-12-22T02:42:43ZengPublic Library of Science (PLoS)PLoS Biology1544-91731545-78852022-10-012010e300181710.1371/journal.pbio.3001817Heliorhodopsin binds and regulates glutamine synthetase activity.Shin-Gyu ChoMyungchul SongKimleng ChuonJin-Gon ShimSeanghun MeasKwang-Hwan JungPhotoreceptors are light-sensitive proteins found in various organisms that respond to light and relay signals into the cells. Heliorhodopsin, a retinal-binding membrane protein, has been recently discovered, however its function remains unknown. Herein, we investigated the relationship between Actinobacteria bacterium IMCC26103 heliorhodopsin (AbHeR) and an adjacent glutamine synthetase (AbGS) in the same operon. We demonstrate that AbHeR binds to AbGS and regulates AbGS activity. More specifically, the dissociation constant (Kd) value of the binding between AbHeR and AbGS is 6.06 μM. Moreover, the absence of positively charged residues within the intracellular loop of AbHeR impacted Kd value as they serve as critical binding sites for AbGS. We also confirm that AbHeR up-regulates the biosynthetic enzyme activity of AbGS both in vitro and in vivo in the presence of light. GS is a key enzyme involved in nitrogen assimilation that catalyzes the conversion of glutamate and ammonia to glutamine. Hence, the interaction between AbHeR and AbGS may be critical for nitrogen assimilation in Actinobacteria bacterium IMCC26103 as it survives in low-nutrient environments. Overall, the findings of our study describe, for the first time, to the best of our knowledge, a novel function of heliorhodopsin as a regulatory rhodopsin with the capacity to bind and regulate enzyme activity required for nitrogen assimilation.https://doi.org/10.1371/journal.pbio.3001817 |
| spellingShingle | Shin-Gyu Cho Myungchul Song Kimleng Chuon Jin-Gon Shim Seanghun Meas Kwang-Hwan Jung Heliorhodopsin binds and regulates glutamine synthetase activity. PLoS Biology |
| title | Heliorhodopsin binds and regulates glutamine synthetase activity. |
| title_full | Heliorhodopsin binds and regulates glutamine synthetase activity. |
| title_fullStr | Heliorhodopsin binds and regulates glutamine synthetase activity. |
| title_full_unstemmed | Heliorhodopsin binds and regulates glutamine synthetase activity. |
| title_short | Heliorhodopsin binds and regulates glutamine synthetase activity. |
| title_sort | heliorhodopsin binds and regulates glutamine synthetase activity |
| url | https://doi.org/10.1371/journal.pbio.3001817 |
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