Primary cilia are key regulators of embryo development and tissue homeostasis. However, their mechanisms and functions, particularly in the context of human cells, are still unclear. Here, we analyzed the consequences of primary cilia modulation for human pluripotent stem cells (hPSCs) proliferation and differentiation. We report that neither activation of the cilia-associated Hedgehog signaling pathway nor ablation of primary cilia by CRISPR gene editing to knockout Tau Tubulin Kinase 2 (TTBK2), a crucial ciliogenesis regulator, affects the self-renewal of hPSCs. Further, we show that TTBK1, a related kinase without previous links to ciliogenesis, is upregulated during hPSCs-derived neural rosette differentiation. Importantly, we demonstrate that while TTBK1 fails to localize to the mother centriole, it regulates primary cilia formation in the differentiated, but not the undifferentiated hPSCs. Finally, we show that TTBK1/2 and primary cilia are implicated in the regulation of the size of hPSCs-derived neural rosettes.

• MeSH
• centrioly metabolismus   MeSH
• cilie metabolismus   MeSH
• lidé MeSH
• pluripotentní kmenové buňky * metabolismus   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny hedgehog * genetika   metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• protein-serin-threoninkinasy MeSH
• proteiny hedgehog * MeSH
• tau-tubulin kinase MeSH Prohlížeč

Primary cilia are hair-like sensory organelles protruding from the surface of most human cells. As cilia are dynamic, several aspects of their biology can only be revealed by real-time analysis in living cells. Here we describe the generation of primary cilia reporter cell lines. Furthermore, we provide a detailed protocol of how to use the reporter cell lines for live-cell imaging microscopy analysis of primary cilia to study their growth as well as intraciliary transport. For complete details on the use and execution of this protocol, please refer to Bernatik et al. (2020) and Pejskova et al. (2020).

• Klíčová slova
• Cell Biology, Cell culture, Microscopy, Molecular Biology,
• MeSH
• buněčné linie MeSH
• cilie * metabolismus   MeSH
• lidé MeSH
• mikroskopie metody   MeSH
• počítačové zpracování obrazu * metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cilia formation is essential for human life. One of the earliest events in the ciliogenesis program is the recruitment of tau-tubulin kinase 2 (TTBK2) by the centriole distal appendage component CEP164. Due to the lack of high-resolution structural information on this complex, it is unclear how it is affected in human ciliopathies such as nephronophthisis. Furthermore, it is poorly understood if binding to CEP164 influences TTBK2 activities. Here, we present a detailed biochemical, structural, and functional analysis of the CEP164-TTBK2 complex and demonstrate how it is compromised by two ciliopathic mutations in CEP164. Moreover, we also provide insights into how binding to CEP164 is coordinated with TTBK2 activities. Together, our data deepen our understanding of a crucial step in cilia formation and will inform future studies aimed at restoring CEP164 functionality in a debilitating human ciliopathy.

• Klíčová slova
• CEP164, TTBK2, basal body, centriole, centrosome, cilia, ciliogenesis, ciliopathy, distal appendage, nephronophthisis,
• MeSH
• ciliopatie genetika   MeSH
• cirkulární dichroismus MeSH
• HEK293 buňky MeSH
• konformace proteinů MeSH
• lidé MeSH
• mikrotubulární proteiny chemie   genetika   metabolismus   MeSH
• molekulární modely MeSH
• mutace * MeSH
• protein-serin-threoninkinasy chemie   metabolismus   MeSH
• proteinové domény MeSH
• proteiny asociované s mikrotubuly metabolismus   MeSH
• stabilita proteinů MeSH
• vazba proteinů MeSH
• vazebná místa MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• CEP164 protein, human MeSH Prohlížeč
• MAPRE1 protein, human MeSH Prohlížeč
• mikrotubulární proteiny MeSH
• protein-serin-threoninkinasy MeSH
• proteiny asociované s mikrotubuly MeSH
• tau-tubulin kinase MeSH Prohlížeč

Primary cilia act as crucial regulators of embryo development and tissue homeostasis. They are instrumental for modulation of several signaling pathways, including Hedgehog, WNT, and TGF-β. However, gaps exist in our understanding of how cilia formation and function is regulated. Recent work has implicated WNT/β-catenin signaling pathway in the regulation of ciliogenesis, yet the results are conflicting. One model suggests that WNT/β-catenin signaling negatively regulates cilia formation, possibly via effects on cell cycle. In contrast, second model proposes a positive role of WNT/β-catenin signaling on cilia formation, mediated by the re-arrangement of centriolar satellites in response to phosphorylation of the key component of WNT/β-catenin pathway, β-catenin. To clarify these discrepancies, we investigated possible regulation of primary cilia by the WNT/β-catenin pathway in cell lines (RPE-1, NIH3T3, and HEK293) commonly used to study ciliogenesis. We used WNT3a to activate or LGK974 to block the pathway, and examined initiation of ciliogenesis, cilium length, and percentage of ciliated cells. We show that the treatment by WNT3a has no- or lesser inhibitory effect on cilia formation. Importantly, the inhibition of secretion of endogenous WNT ligands using LGK974 blocks WNT signaling but does not affect ciliogenesis. Finally, using knock-out cells for key WNT pathway components, namely DVL1/2/3, LRP5/6, or AXIN1/2 we show that neither activation nor deactivation of the WNT/β-catenin pathway affects the process of ciliogenesis. These results suggest that WNT/β-catenin-mediated signaling is not generally required for efficient cilia formation. In fact, activation of the WNT/β-catenin pathway in some systems seems to moderately suppress ciliogenesis.

• Klíčová slova
• HEK293, NIH3T3, RPE-1, Wnt/β-catenin, Wnt3a, cell signaling, ciliogenesis, primary cilia,
• Publikační typ
• časopisecké články MeSH

Primary cilia play critical roles in development and disease. Their assembly and disassembly are tightly coupled to cell cycle progression. Here, we present data identifying KIF14 as a regulator of cilia formation and Hedgehog (HH) signaling. We show that RNAi depletion of KIF14 specifically leads to defects in ciliogenesis and basal body (BB) biogenesis, as its absence hampers the efficiency of primary cilium formation and the dynamics of primary cilium elongation, and disrupts the localization of the distal appendage proteins SCLT1 and FBF1 and components of the IFT-B complex. We identify deregulated Aurora A activity as a mechanism contributing to the primary cilium and BB formation defects seen after KIF14 depletion. In addition, we show that primary cilia in KIF14-depleted cells are defective in response to HH pathway activation, independently of the effects of Aurora A. In sum, our data point to KIF14 as a critical node connecting cell cycle machinery, effective ciliogenesis, and HH signaling.

• MeSH
• adaptorové proteiny signální transdukční metabolismus   MeSH
• aurora kinasa A antagonisté a inhibitory   genetika   metabolismus   MeSH
• bazální tělíska metabolismus   MeSH
• buněčný cyklus genetika   MeSH
• chromatografie kapalinová MeSH
• cilie genetika   metabolismus   patologie   MeSH
• HEK293 buňky MeSH
• interfáze fyziologie   MeSH
• intracelulární signální peptidy a proteiny genetika   metabolismus   MeSH
• kineziny genetika   metabolismus   MeSH
• lidé MeSH
• mitóza genetika   MeSH
• onkogenní proteiny genetika   metabolismus   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   MeSH
• proteiny hedgehog metabolismus   MeSH
• RNA interference MeSH
• signální transdukce genetika   MeSH
• sodíkové kanály metabolismus   MeSH
• tandemová hmotnostní spektrometrie MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• adaptorové proteiny signální transdukční MeSH
• AURKA protein, human MeSH Prohlížeč
• aurora kinasa A MeSH
• citron-kinase MeSH Prohlížeč
• FBF1 protein, human MeSH Prohlížeč
• intracelulární signální peptidy a proteiny MeSH
• KIF14 protein, human MeSH Prohlížeč
• kineziny MeSH
• onkogenní proteiny MeSH
• protein-serin-threoninkinasy MeSH
• proteiny hedgehog MeSH
• SCLT1 protein, human MeSH Prohlížeč
• sodíkové kanály MeSH

Primary cilia are organelles necessary for proper implementation of developmental and homeostasis processes. To initiate their assembly, coordinated actions of multiple proteins are needed. Tau tubulin kinase 2 (TTBK2) is a key player in the cilium assembly pathway, controlling the final step of cilia initiation. The function of TTBK2 in ciliogenesis is critically dependent on its kinase activity; however, the precise mechanism of TTBK2 action has so far not been fully understood due to the very limited information about its relevant substrates. In this study, we demonstrate that CEP83, CEP89, CCDC92, Rabin8, and DVL3 are substrates of TTBK2 kinase activity. Further, we characterize a set of phosphosites of those substrates and CEP164 induced by TTBK2 in vitro and in vivo. Intriguingly, we further show that identified TTBK2 phosphosites and consensus sequence delineated from those are distinct from motifs previously assigned to TTBK2. Finally, we show that TTBK2 is also required for efficient phosphorylation of many S/T sites in CEP164 and provide evidence that TTBK2-induced phosphorylations of CEP164 modulate its function, which in turn seems relevant for the process of cilia formation. In summary, our work provides important insight into the substrates-TTBK2 kinase relationship and suggests that phosphorylation of substrates on multiple sites by TTBK2 is probably involved in the control of ciliogenesis in human cells.

• MeSH
• aminokyselinové motivy MeSH
• cilie metabolismus   MeSH
• fosforylace MeSH
• fosfoserin metabolismus   MeSH
• fosfothreonin metabolismus   MeSH
• HEK293 buňky MeSH
• kasein kinasa I metabolismus   MeSH
• lidé MeSH
• multiproteinové komplexy metabolismus   MeSH
• organogeneze * MeSH
• protein-serin-threoninkinasy chemie   metabolismus   MeSH
• substrátová specifita MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• fosfoserin MeSH
• fosfothreonin MeSH
• kasein kinasa I MeSH
• multiproteinové komplexy MeSH
• protein-serin-threoninkinasy MeSH
• tau-tubulin kinase MeSH Prohlížeč

BACKGROUND: Dishevelled (DVL) is an essential component of the Wnt signaling cascades. Function of DVL is controlled by phosphorylation but the molecular details are missing. DVL3 contains 131 serines and threonines whose phosphorylation generates complex barcodes underlying diverse DVL3 functions. In order to dissect the role of DVL phosphorylation we analyzed the phosphorylation of human DVL3 induced by previously reported (CK1ε, NEK2, PLK1, CK2α, RIPK4, PKCδ) and newly identified (TTBK2, Aurora A) DVL kinases. METHODS: Shotgun proteomics including TiO2 enrichment of phosphorylated peptides followed by liquid chromatography tandem mass spectrometry on immunoprecipitates from HEK293T cells was used to identify and quantify phosphorylation of DVL3 protein induced by 8 kinases. Functional characterization was performed by in-cell analysis of phospho-mimicking/non-phosphorylatable DVL3 mutants and supported by FRET assays and NMR spectroscopy. RESULTS: We used quantitative mass spectrometry and calculated site occupancies and quantified phosphorylation of > 80 residues. Functional validation demonstrated the importance of CK1ε-induced phosphorylation of S268 and S311 for Wnt-3a-induced β-catenin activation. S630-643 cluster phosphorylation by CK1, NEK2 or TTBK2 is essential for even subcellular distribution of DVL3 when induced by CK1 and TTBK2 but not by NEK2. Further investigation showed that NEK2 utilizes a different mechanism to promote even localization of DVL3. NEK2 triggered phosphorylation of PDZ domain at S263 and S280 prevents binding of DVL C-terminus to PDZ and promotes an open conformation of DVL3 that is more prone to even subcellular localization. CONCLUSIONS: We identify unique phosphorylation barcodes associated with DVL function. Our data provide an example of functional synergy between phosphorylation in structured domains and unstructured IDRs that together dictate the biological outcome. Video Abtract.

• Klíčová slova
• CK1, DVL3, Dishevelled, Kinase, Mass spectrometry, NEK2, Phosphorylation, TTBK2, Wnt,
• MeSH
• fosforylace MeSH
• HEK293 buňky MeSH
• hmotnostní spektrometrie MeSH
• kinasy NEK metabolismus   MeSH
• konformace proteinů MeSH
• kultivované buňky MeSH
• lidé MeSH
• protein dishevelled chemie   metabolismus   MeSH
• signální transdukce MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• srovnávací studie MeSH
• Názvy látek
• DVL3 protein, human MeSH Prohlížeč
• kinasy NEK MeSH
• NEK2 protein, human MeSH Prohlížeč
• protein dishevelled MeSH

Wnt signaling cascade has developed together with multicellularity to orchestrate the development and homeostasis of complex structures. Wnt pathway components - such as β-catenin, Dishevelled (DVL), Lrp6, and Axin-- are often dedicated proteins that emerged in evolution together with the Wnt signaling cascade and are believed to function primarily in the Wnt cascade. It is interesting to see that in recent literature many of these proteins are connected with cellular functions that are more ancient and not limited to multicellular organisms - such as cell cycle regulation, centrosome biology, or cell division. In this review, we summarize the recent literature describing this crosstalk. Specifically, we attempt to find the answers to the following questions: Is the response to Wnt ligands regulated by the cell cycle? Is the centrosome and/or cilium required to activate the Wnt pathway? How do Wnt pathway components regulate the centrosomal cycle and cilia formation and function? We critically review the evidence that describes how these connections are regulated and how they help to integrate cell-to-cell communication with the cell and the centrosomal cycle in order to achieve a fine-tuned, physiological response.

• Klíčová slova
• Wnt, cell cycle, centrosome, cilium, crosstalk, planar cell polarity,
• MeSH
• buněčný cyklus * MeSH
• centrozom metabolismus   MeSH
• lidé MeSH
• mezibuněčná komunikace MeSH
• polarita buněk MeSH
• signální dráha Wnt * MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH