The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity
Members of the ubiquitous COX11 (cytochrome c oxidase 11) protein family are involved in copper delivery to the COX complex. In this work, we characterize the Arabidopsis thaliana COX11 homolog (encoded by locus At1g02410). Western blot analyses and confocal microscopy identified Arabidopsis COX11 a...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2015-12-01
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| Series: | Frontiers in Plant Science |
| Subjects: | |
| Online Access: | http://journal.frontiersin.org/Journal/10.3389/fpls.2015.01091/full |
| _version_ | 1828806358274670592 |
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| author | Ivan eRadin Natanael eMansilla Gerhard eRödel Iris eSteinebrunner |
| author_facet | Ivan eRadin Natanael eMansilla Gerhard eRödel Iris eSteinebrunner |
| author_sort | Ivan eRadin |
| collection | DOAJ |
| description | Members of the ubiquitous COX11 (cytochrome c oxidase 11) protein family are involved in copper delivery to the COX complex. In this work, we characterize the Arabidopsis thaliana COX11 homolog (encoded by locus At1g02410). Western blot analyses and confocal microscopy identified Arabidopsis COX11 as an integral mitochondrial protein. Despite sharing high sequence and structural similarities, the Arabidopsis COX11 is not able to functionally replace the Saccharomyces cerevisiae COX11 homolog. Nevertheless, further analysis confirmed the hypothesis that Arabidopsis COX11 is essential for COX activity. Disturbance of COX11 expression through knockdown (KD) or overexpression (OE) affected COX activity. In KD lines, the activity was reduced by ~50%, resulting in root growth inhibition, smaller rosettes and leaf curling. In OE lines, the reduction was less pronounced (~80% of the wild type), still resulting in root growth inhibition. Additionally, pollen germination was impaired in COX11 KD and OE plants. This effect on pollen germination can only partially be attributed to COX deficiency and may indicate a possible auxiliary role of COX11 in ROS metabolism. In agreement with its role in energy production, the COX11 promoter is highly active in cells and tissues with high-energy demand for example shoot and root meristems or vascular tissues of source and sink organs. In COX11 KD lines, the expression of the plasma-membrane copper transporter COPT2 and of several copper chaperones was upregulated, indicative of a retrograde signaling pathway pertinent to copper homeostasis. Based on our data, we postulate that COX11 is a mitochondrial chaperone, which plays an important role for plant growth and pollen germination as essential COX complex assembly factor. |
| first_indexed | 2024-12-12T08:08:36Z |
| format | Article |
| id | doaj.art-d44d9290d6df4885bec40dc43f0b9f20 |
| institution | Directory Open Access Journal |
| issn | 1664-462X |
| language | English |
| last_indexed | 2024-12-12T08:08:36Z |
| publishDate | 2015-12-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Plant Science |
| spelling | doaj.art-d44d9290d6df4885bec40dc43f0b9f202022-12-22T00:31:53ZengFrontiers Media S.A.Frontiers in Plant Science1664-462X2015-12-01610.3389/fpls.2015.01091159301The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activityIvan eRadin0Natanael eMansilla1Gerhard eRödel2Iris eSteinebrunner3Technische Universität DresdenUniversidad Nacional del LitoralTechnische Universität DresdenTechnische Universität DresdenMembers of the ubiquitous COX11 (cytochrome c oxidase 11) protein family are involved in copper delivery to the COX complex. In this work, we characterize the Arabidopsis thaliana COX11 homolog (encoded by locus At1g02410). Western blot analyses and confocal microscopy identified Arabidopsis COX11 as an integral mitochondrial protein. Despite sharing high sequence and structural similarities, the Arabidopsis COX11 is not able to functionally replace the Saccharomyces cerevisiae COX11 homolog. Nevertheless, further analysis confirmed the hypothesis that Arabidopsis COX11 is essential for COX activity. Disturbance of COX11 expression through knockdown (KD) or overexpression (OE) affected COX activity. In KD lines, the activity was reduced by ~50%, resulting in root growth inhibition, smaller rosettes and leaf curling. In OE lines, the reduction was less pronounced (~80% of the wild type), still resulting in root growth inhibition. Additionally, pollen germination was impaired in COX11 KD and OE plants. This effect on pollen germination can only partially be attributed to COX deficiency and may indicate a possible auxiliary role of COX11 in ROS metabolism. In agreement with its role in energy production, the COX11 promoter is highly active in cells and tissues with high-energy demand for example shoot and root meristems or vascular tissues of source and sink organs. In COX11 KD lines, the expression of the plasma-membrane copper transporter COPT2 and of several copper chaperones was upregulated, indicative of a retrograde signaling pathway pertinent to copper homeostasis. Based on our data, we postulate that COX11 is a mitochondrial chaperone, which plays an important role for plant growth and pollen germination as essential COX complex assembly factor.http://journal.frontiersin.org/Journal/10.3389/fpls.2015.01091/fullMitochondriaArabidopsis thalianaroot developmentPollen developmentcopper chaperoneCOX complex |
| spellingShingle | Ivan eRadin Natanael eMansilla Gerhard eRödel Iris eSteinebrunner The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity Frontiers in Plant Science Mitochondria Arabidopsis thaliana root development Pollen development copper chaperone COX complex |
| title | The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity |
| title_full | The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity |
| title_fullStr | The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity |
| title_full_unstemmed | The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity |
| title_short | The Arabidopsis COX11 homolog is essential for cytochrome c oxidase activity |
| title_sort | arabidopsis cox11 homolog is essential for cytochrome c oxidase activity |
| topic | Mitochondria Arabidopsis thaliana root development Pollen development copper chaperone COX complex |
| url | http://journal.frontiersin.org/Journal/10.3389/fpls.2015.01091/full |
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