Limits...
Deacetylation of α-tubulin and cortactin is required for HDAC6 to trigger ciliary disassembly.

Ran J, Yang Y, Li D, Liu M, Zhou J - Sci Rep (2015)

Bottom Line: Ciliary dysfunction is associated with a variety of diseases known as ciliopathies.Overexpression of HDAC6 decreases the levels of acetylated α-tubulin and cortactin without affecting the expression or localization of known ciliary regulators.These findings provide mechanistic insight into the ciliary role of HDAC6 and underscore the importance of reversible acetylation in regulating ciliary homeostasis.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China.

ABSTRACT
Cilia play important roles in sensing extracellular signals and directing fluid flow. Ciliary dysfunction is associated with a variety of diseases known as ciliopathies. Histone deacetylase 6 (HDAC6) has recently emerged as a major driver of ciliary disassembly, but little is known about the downstream players. Here we provide the first evidence that HDAC6-mediated deacetylation of α-tubulin and cortactin is critical for its induction of ciliary disassembly. HDAC6 is localized in the cytoplasm and enriched at the centrosome and basal body. Overexpression of HDAC6 decreases the levels of acetylated α-tubulin and cortactin without affecting the expression or localization of known ciliary regulators. We also find that overexpression of α-tubulin or cortactin or their acetylation-deficient mutants enhances the ability of HDAC6 to induce ciliary disassembly. In addition, acetylation-mimicking mutants of α-tubulin and cortactin counteract HDAC6-induced ciliary disassembly. Furthermore, HDAC6 stimulates actin polymerization, and inhibition of actin polymerization abolishes the activity of HDAC6 to trigger ciliary disassembly. These findings provide mechanistic insight into the ciliary role of HDAC6 and underscore the importance of reversible acetylation in regulating ciliary homeostasis.

No MeSH data available.


Inhibition of actin polymerization abrogates HDAC6-mediated ciliary disassembly.(A–C) Immunofluorescence images (A), percentage of ciliated cells (B), and ciliary length (C) in RPE1 cells transfected with GFP-HDAC6 and Flag vector or Flag-cortactin wild-type (WT), 9KQ, or 9KR, starved in serum-free medium with cytochalasin D (CytD, 5 mM) for 24 hours, and stained with acetylated α-tubulin and Flag antibodies and DAPI. Scale bar, 5 μm. (D–F) Immunofluorescence images (D), percentage of ciliated cells (E), and ciliary length (F) in RPE1 cells transfected with GFP vector or GFP-HDAC6, starved in serum-free medium with cytochalasin D (5 mM) or vehicle control for 24 hours, and stained with acetylated α-tubulin antibody and DAPI. Scale bar, 5 μm. ***P < 0.001; ns, not significant. Error bars indicate SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4526867&req=5

f9: Inhibition of actin polymerization abrogates HDAC6-mediated ciliary disassembly.(A–C) Immunofluorescence images (A), percentage of ciliated cells (B), and ciliary length (C) in RPE1 cells transfected with GFP-HDAC6 and Flag vector or Flag-cortactin wild-type (WT), 9KQ, or 9KR, starved in serum-free medium with cytochalasin D (CytD, 5 mM) for 24 hours, and stained with acetylated α-tubulin and Flag antibodies and DAPI. Scale bar, 5 μm. (D–F) Immunofluorescence images (D), percentage of ciliated cells (E), and ciliary length (F) in RPE1 cells transfected with GFP vector or GFP-HDAC6, starved in serum-free medium with cytochalasin D (5 mM) or vehicle control for 24 hours, and stained with acetylated α-tubulin antibody and DAPI. Scale bar, 5 μm. ***P < 0.001; ns, not significant. Error bars indicate SEM.

Mentions: Since branched F-actin is known to inhibit ciliogenesis343536, we sought to investigate whether HDAC6/deacetylated cortactin-mediated increase of actin polymerization contributes to HDAC6-mediated ciliary disassembly. RPE1 cells were transfected with GFP-HDAC6 and Flag-cortactin wild-type, 9KQ, or 9KR, and then treated with cytochalasin D, a well-known inhibitor of actin polymerization. We found that cytochalasin D dramatically abolished the effect of cortactin on HDAC6-mediated ciliary disassembly (Fig. 9A–C).


Deacetylation of α-tubulin and cortactin is required for HDAC6 to trigger ciliary disassembly.

Ran J, Yang Y, Li D, Liu M, Zhou J - Sci Rep (2015)

Inhibition of actin polymerization abrogates HDAC6-mediated ciliary disassembly.(A–C) Immunofluorescence images (A), percentage of ciliated cells (B), and ciliary length (C) in RPE1 cells transfected with GFP-HDAC6 and Flag vector or Flag-cortactin wild-type (WT), 9KQ, or 9KR, starved in serum-free medium with cytochalasin D (CytD, 5 mM) for 24 hours, and stained with acetylated α-tubulin and Flag antibodies and DAPI. Scale bar, 5 μm. (D–F) Immunofluorescence images (D), percentage of ciliated cells (E), and ciliary length (F) in RPE1 cells transfected with GFP vector or GFP-HDAC6, starved in serum-free medium with cytochalasin D (5 mM) or vehicle control for 24 hours, and stained with acetylated α-tubulin antibody and DAPI. Scale bar, 5 μm. ***P < 0.001; ns, not significant. Error bars indicate SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4526867&req=5

f9: Inhibition of actin polymerization abrogates HDAC6-mediated ciliary disassembly.(A–C) Immunofluorescence images (A), percentage of ciliated cells (B), and ciliary length (C) in RPE1 cells transfected with GFP-HDAC6 and Flag vector or Flag-cortactin wild-type (WT), 9KQ, or 9KR, starved in serum-free medium with cytochalasin D (CytD, 5 mM) for 24 hours, and stained with acetylated α-tubulin and Flag antibodies and DAPI. Scale bar, 5 μm. (D–F) Immunofluorescence images (D), percentage of ciliated cells (E), and ciliary length (F) in RPE1 cells transfected with GFP vector or GFP-HDAC6, starved in serum-free medium with cytochalasin D (5 mM) or vehicle control for 24 hours, and stained with acetylated α-tubulin antibody and DAPI. Scale bar, 5 μm. ***P < 0.001; ns, not significant. Error bars indicate SEM.
Mentions: Since branched F-actin is known to inhibit ciliogenesis343536, we sought to investigate whether HDAC6/deacetylated cortactin-mediated increase of actin polymerization contributes to HDAC6-mediated ciliary disassembly. RPE1 cells were transfected with GFP-HDAC6 and Flag-cortactin wild-type, 9KQ, or 9KR, and then treated with cytochalasin D, a well-known inhibitor of actin polymerization. We found that cytochalasin D dramatically abolished the effect of cortactin on HDAC6-mediated ciliary disassembly (Fig. 9A–C).

Bottom Line: Ciliary dysfunction is associated with a variety of diseases known as ciliopathies.Overexpression of HDAC6 decreases the levels of acetylated α-tubulin and cortactin without affecting the expression or localization of known ciliary regulators.These findings provide mechanistic insight into the ciliary role of HDAC6 and underscore the importance of reversible acetylation in regulating ciliary homeostasis.

View Article: PubMed Central - PubMed

Affiliation: State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai University, Tianjin 300071, China.

ABSTRACT
Cilia play important roles in sensing extracellular signals and directing fluid flow. Ciliary dysfunction is associated with a variety of diseases known as ciliopathies. Histone deacetylase 6 (HDAC6) has recently emerged as a major driver of ciliary disassembly, but little is known about the downstream players. Here we provide the first evidence that HDAC6-mediated deacetylation of α-tubulin and cortactin is critical for its induction of ciliary disassembly. HDAC6 is localized in the cytoplasm and enriched at the centrosome and basal body. Overexpression of HDAC6 decreases the levels of acetylated α-tubulin and cortactin without affecting the expression or localization of known ciliary regulators. We also find that overexpression of α-tubulin or cortactin or their acetylation-deficient mutants enhances the ability of HDAC6 to induce ciliary disassembly. In addition, acetylation-mimicking mutants of α-tubulin and cortactin counteract HDAC6-induced ciliary disassembly. Furthermore, HDAC6 stimulates actin polymerization, and inhibition of actin polymerization abolishes the activity of HDAC6 to trigger ciliary disassembly. These findings provide mechanistic insight into the ciliary role of HDAC6 and underscore the importance of reversible acetylation in regulating ciliary homeostasis.

No MeSH data available.