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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.


HDAC6 is enriched at the centrosome and basal body.(A) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 antibody and DAPI. Scale bar, 5 μm. (B) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 and γ-tubulin antibodies and DAPI. Scale bar, 5 μm.
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f1: HDAC6 is enriched at the centrosome and basal body.(A) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 antibody and DAPI. Scale bar, 5 μm. (B) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 and γ-tubulin antibodies and DAPI. Scale bar, 5 μm.

Mentions: In this study, we analyzed the ciliary role of HDAC6 using hTERT-RPE1 cells (human telomerase-immortalized retinal pigment epithelial cells, hereinafter referred to as RPE1 cells), which are known to form primary cilia when cultured in the serum-free medium and have been widely used to investigate various aspects of cilia. Immunofluorescence staining with HDAC6 antibody or double staining with HDAC6 and γ-tubulin antibodies revealed that HDAC6 was localized in the cytoplasm and enriched at the centrosome and basal body (Fig. 1A,B). Both the percentage of ciliated cells and the length of cilia were significantly decreased by transfection with HA-HDAC6, compared with transfection with HA vector (Fig. 2A–C). Similar results were obtained by transfection of cells with GFP-HDAC6 (Fig. 2D–F). To further study the ciliary role of HDAC6, we depleted its expression by using two different siRNAs (Fig. 2G,H). Interestingly, loss of HDAC6 did not obviously affect the percentage of ciliated cells or the length of cilia (Fig. 2I–K). These results are in agreement with previous findings that the primary role of HDAC6 lies in ciliary disassembly567891011121314151617.


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)

HDAC6 is enriched at the centrosome and basal body.(A) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 antibody and DAPI. Scale bar, 5 μm. (B) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 and γ-tubulin antibodies and DAPI. Scale bar, 5 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f1: HDAC6 is enriched at the centrosome and basal body.(A) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 antibody and DAPI. Scale bar, 5 μm. (B) Immunofluorescence images of RPE1 cells cultured with or without serum for 24 hours and stained with HDAC6 and γ-tubulin antibodies and DAPI. Scale bar, 5 μm.
Mentions: In this study, we analyzed the ciliary role of HDAC6 using hTERT-RPE1 cells (human telomerase-immortalized retinal pigment epithelial cells, hereinafter referred to as RPE1 cells), which are known to form primary cilia when cultured in the serum-free medium and have been widely used to investigate various aspects of cilia. Immunofluorescence staining with HDAC6 antibody or double staining with HDAC6 and γ-tubulin antibodies revealed that HDAC6 was localized in the cytoplasm and enriched at the centrosome and basal body (Fig. 1A,B). Both the percentage of ciliated cells and the length of cilia were significantly decreased by transfection with HA-HDAC6, compared with transfection with HA vector (Fig. 2A–C). Similar results were obtained by transfection of cells with GFP-HDAC6 (Fig. 2D–F). To further study the ciliary role of HDAC6, we depleted its expression by using two different siRNAs (Fig. 2G,H). Interestingly, loss of HDAC6 did not obviously affect the percentage of ciliated cells or the length of cilia (Fig. 2I–K). These results are in agreement with previous findings that the primary role of HDAC6 lies in ciliary disassembly567891011121314151617.

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.