Tau is an intrinsically disordered microtubule-associated protein (MAP) implicated in neurodegenerative disease. On microtubules, tau molecules segregate into two kinetically distinct phases, consisting of either independently diffusing molecules or interacting molecules that form cohesive 'envelopes' around microtubules. Envelopes differentially regulate lattice accessibility for other MAPs, but the mechanism of envelope formation remains unclear. Here we find that tau envelopes form cooperatively, locally altering the spacing of tubulin dimers within the microtubule lattice. Envelope formation compacted the underlying lattice, whereas lattice extension induced tau envelope disassembly. Investigating other members of the tau family, we find that MAP2 similarly forms envelopes governed by lattice spacing, whereas MAP4 cannot. Envelopes differentially biased motor protein movement, suggesting that tau family members could spatially divide the microtubule surface into functionally distinct regions. We conclude that the interdependent allostery between lattice spacing and cooperative envelope formation provides the molecular basis for spatial regulation of microtubule-based processes by tau and MAP2.

• MeSH
• lidé MeSH
• mikrotubuly metabolismus   MeSH
• neurodegenerativní nemoci * metabolismus   MeSH
• proteiny asociované s mikrotubuly metabolismus   MeSH
• proteiny tau * metabolismus   MeSH
• proteiny metabolismus   MeSH
• tubulin metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• proteiny asociované s mikrotubuly MeSH
• proteiny tau * MeSH
• proteiny MeSH
• tubulin MeSH

Histone deacetylase 6 (HDAC6) is a multidomain cytosolic enzyme having tubulin deacetylase activity that has been unequivocally assigned to the second of the tandem catalytic domains. However, virtually no information exists on the contribution of other HDAC6 domains on tubulin recognition. Here, using recombinant protein expression, site-directed mutagenesis, fluorimetric and biochemical assays, microscale thermophoresis, and total internal reflection fluorescence microscopy, we identified the N-terminal, disordered region of HDAC6 as a microtubule-binding domain and functionally characterized it to the single-molecule level. We show that the microtubule-binding motif spans two positively charged patches comprising residues Lys-32 to Lys-58. We found that HDAC6-microtubule interactions are entirely independent of the catalytic domains and are mediated by ionic interactions with the negatively charged microtubule surface. Importantly, a crosstalk between the microtubule-binding domain and the deacetylase domain was critical for recognition and efficient deacetylation of free tubulin dimers both in vitro and in vivo Overall, our results reveal that recognition of substrates by HDAC6 is more complex than previously appreciated and that domains outside the tandem catalytic core are essential for proficient substrate deacetylation.

• Klíčová slova
• cytoskeleton, histone deacetylase 6 (HDAC6), intrinsically disordered protein, microtubule-associated protein (MAP), post-translational modification, protein motif, protein-protein interaction, structure-function, substrate specificity, total internal reflection fluorescence (TIRF), tubulin,
• MeSH
• acetylace MeSH
• histondeacetylasa 6 metabolismus   MeSH
• katalytická doména MeSH
• lidé MeSH
• mikrotubuly metabolismus   MeSH
• proteinové domény fyziologie   MeSH
• sekvence aminokyselin MeSH
• substrátová specifita MeSH
• tubulin metabolismus   MeSH
• vazba proteinů MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• HDAC6 protein, human MeSH Prohlížeč
• histondeacetylasa 6 MeSH
• tubulin MeSH