Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons
An important post-translational modification (PTM) of α-tubulin is the removal of amino acids from its C-terminus. Removal of the C-terminal tyrosine residue yields detyrosinated α-tubulin, and subsequent removal of the penultimate glutamate residue produces ΔC2-α-tubulin. These PTMs alter the abili...
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| Format: | Article |
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MDPI AG
2023-02-01
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| Series: | Biomolecules |
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| Online Access: | https://www.mdpi.com/2218-273X/13/2/357 |
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| author | Takashi Hotta Alexandra Plemmons Margo Gebbie Trevor A. Ziehm Teresa Lynne Blasius Craig Johnson Kristen J. Verhey Jillian N. Pearring Ryoma Ohi |
| author_facet | Takashi Hotta Alexandra Plemmons Margo Gebbie Trevor A. Ziehm Teresa Lynne Blasius Craig Johnson Kristen J. Verhey Jillian N. Pearring Ryoma Ohi |
| author_sort | Takashi Hotta |
| collection | DOAJ |
| description | An important post-translational modification (PTM) of α-tubulin is the removal of amino acids from its C-terminus. Removal of the C-terminal tyrosine residue yields detyrosinated α-tubulin, and subsequent removal of the penultimate glutamate residue produces ΔC2-α-tubulin. These PTMs alter the ability of the α-tubulin C-terminal tail to interact with effector proteins and are thereby thought to change microtubule dynamics, stability, and organization. The peptidase(s) that produces ΔC2-α-tubulin in a physiological context remains unclear. Here, we take advantage of the observation that ΔC2-α-tubulin accumulates to high levels in cells lacking tubulin tyrosine ligase (TTL) to screen for cytosolic carboxypeptidases (CCPs) that generate ΔC2-α-tubulin. We identify CCP1 as the sole peptidase that produces ΔC2-α-tubulin in <i>TTLΔ</i> HeLa cells. Interestingly, we find that the levels of ΔC2-α-tubulin are only modestly reduced in photoreceptors of <i>ccp1<sup>−/−</sup></i> mice, indicating that other peptidases act synergistically with CCP1 to produce ΔC2-α-tubulin in post-mitotic cells. Moreover, the production of ΔC2-α-tubulin appears to be under tight spatial control in the photoreceptor cilium: ΔC2-α-tubulin persists in the connecting cilium of <i>ccp1<sup>−/−</sup></i> but is depleted in the distal portion of the photoreceptor. This work establishes the groundwork to pinpoint the function of ΔC2-α-tubulin in proliferating and post-mitotic mammalian cells. |
| first_indexed | 2024-03-11T09:05:38Z |
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| language | English |
| last_indexed | 2024-03-11T09:05:38Z |
| publishDate | 2023-02-01 |
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| series | Biomolecules |
| spelling | doaj.art-104aadece22b49dea3b6ba6d91a872e02023-11-16T19:24:04ZengMDPI AGBiomolecules2218-273X2023-02-0113235710.3390/biom13020357Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor NeuronsTakashi Hotta0Alexandra Plemmons1Margo Gebbie2Trevor A. Ziehm3Teresa Lynne Blasius4Craig Johnson5Kristen J. Verhey6Jillian N. Pearring7Ryoma Ohi8Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Ophthalmology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USADepartment of Cell and Developmental Biology, University of Michigan, Ann Arbor, MI 48109, USAAn important post-translational modification (PTM) of α-tubulin is the removal of amino acids from its C-terminus. Removal of the C-terminal tyrosine residue yields detyrosinated α-tubulin, and subsequent removal of the penultimate glutamate residue produces ΔC2-α-tubulin. These PTMs alter the ability of the α-tubulin C-terminal tail to interact with effector proteins and are thereby thought to change microtubule dynamics, stability, and organization. The peptidase(s) that produces ΔC2-α-tubulin in a physiological context remains unclear. Here, we take advantage of the observation that ΔC2-α-tubulin accumulates to high levels in cells lacking tubulin tyrosine ligase (TTL) to screen for cytosolic carboxypeptidases (CCPs) that generate ΔC2-α-tubulin. We identify CCP1 as the sole peptidase that produces ΔC2-α-tubulin in <i>TTLΔ</i> HeLa cells. Interestingly, we find that the levels of ΔC2-α-tubulin are only modestly reduced in photoreceptors of <i>ccp1<sup>−/−</sup></i> mice, indicating that other peptidases act synergistically with CCP1 to produce ΔC2-α-tubulin in post-mitotic cells. Moreover, the production of ΔC2-α-tubulin appears to be under tight spatial control in the photoreceptor cilium: ΔC2-α-tubulin persists in the connecting cilium of <i>ccp1<sup>−/−</sup></i> but is depleted in the distal portion of the photoreceptor. This work establishes the groundwork to pinpoint the function of ΔC2-α-tubulin in proliferating and post-mitotic mammalian cells.https://www.mdpi.com/2218-273X/13/2/357tubulindetyrosinationΔC2-tubulinVASOHIBINcytosolic carboxypeptidase (CCP) |
| spellingShingle | Takashi Hotta Alexandra Plemmons Margo Gebbie Trevor A. Ziehm Teresa Lynne Blasius Craig Johnson Kristen J. Verhey Jillian N. Pearring Ryoma Ohi Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons Biomolecules tubulin detyrosination ΔC2-tubulin VASOHIBIN cytosolic carboxypeptidase (CCP) |
| title | Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons |
| title_full | Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons |
| title_fullStr | Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons |
| title_full_unstemmed | Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons |
| title_short | Mechanistic Analysis of CCP1 in Generating ΔC2 α-Tubulin in Mammalian Cells and Photoreceptor Neurons |
| title_sort | mechanistic analysis of ccp1 in generating δc2 α tubulin in mammalian cells and photoreceptor neurons |
| topic | tubulin detyrosination ΔC2-tubulin VASOHIBIN cytosolic carboxypeptidase (CCP) |
| url | https://www.mdpi.com/2218-273X/13/2/357 |
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