The intraflagellar transport cycle

Nature Reviews Molecular Cell Biology, Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 13, 2024

Language: Английский

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IFT20 regulates lymphatic endothelial cell-cell junctions via endocytic trafficking of VE-cadherin

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Jan. 15, 2025

Abstract Intraflagellar transport (IFT) proteins are required for the assembly and function of primary cilia. They also regulate non-ciliary polarized vesicular traffic, such as T cell receptor recycling. We recently reported that lymphatic endothelial cells assemble cilia express IFT proteins. Here, we report IFT20 regulates vascular cadherin (VE-cadherin) localization at adherens junctions. deletion caused discontinuous, button-like interendothelial This resulted in excessive lymphangiogenesis impaired lymph drainage mice. In vitro, VEGF-C treatment KD human dermal accumulation VE-cadherin RAB5+ endosomes enhanced sustained VEGFR-3 signaling. Our findings consistent with a model which promotes recycling to junction where it sequesters surface, thereby limiting pro-lymphangiogenic absence IFT20, intercellular junctions destabilized, signaling is enhanced, by intracellular sequestration VE-cadherin. study elucidates an protein provides mechanistic insight into processes cell-cell lymphangiogenic

Language: Английский

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Intraflagellar transport protein IFT172 contains a C-terminal ubiquitin-binding U-box-like domain involved in ciliary signaling

Published: Jan. 31, 2025

Intraflagellar transport (IFT) is a fundamental process driving ciliogenesis in most eukaryotic organisms. IFT172, the largest protein of IFT complex, plays crucial role cilium formation and associated with several disease variants causing ciliopathies. While IFT172 tethered to IFT-B complex via its N-terminal domains, function C-terminal domains has remained elusive. Here, we reveal that part interacts IFT-A subunits, providing molecular basis for bridging complexes. We determine crystal structure uncovering conserved U-box-like domain often found E3 ubiquitin ligases. This exhibits ubiquitin-binding properties auto-ubiquitination activity. The activity reduced C1727R patient ciliopathy variant. use CRISPR-engineered RPE-1 cells demonstrate essential stability proper formation. Notably, heterozygous deletion U-box show altered TGFB signaling responses, particularly SMAD2 phosphorylation levels AKT activation. Our findings suggest novel dual both structural support within trains regulation ciliary ubiquitination pathways, new insights into mechanisms underlying IFT172-related

Language: Английский

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Intraflagellar transport protein IFT172 contains a C-terminal ubiquitin-binding U-box-like domain involved in ciliary signaling

Published: Jan. 31, 2025

Intraflagellar transport (IFT) is a fundamental process driving ciliogenesis in most eukaryotic organisms. IFT172, the largest protein of IFT complex, plays crucial role cilium formation and associated with several disease variants causing ciliopathies. While IFT172 tethered to IFT-B complex via its N-terminal domains, function C-terminal domains has remained elusive. Here, we reveal that part interacts IFT-A subunits, providing molecular basis for bridging complexes. We determine crystal structure uncovering conserved U-box-like domain often found E3 ubiquitin ligases. This exhibits ubiquitin-binding properties auto-ubiquitination activity. The activity reduced C1727R patient ciliopathy variant. use CRISPR-engineered RPE-1 cells demonstrate essential stability proper formation. Notably, heterozygous deletion U-box show altered TGFB signaling responses, particularly SMAD2 phosphorylation levels AKT activation. Our findings suggest novel dual both structural support within trains regulation ciliary ubiquitination pathways, new insights into mechanisms underlying IFT172-related

Language: Английский

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Molecular organization of the distal tip of vertebrate motile cilia

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 19, 2025

Summary The beating of cilia on multi-ciliated cells (MCCs) is essential for normal development and homeostasis in animals. Unlike basal bodies or axonemes, the distal tips MCC remain poorly defined. Here, we characterize molecular organization tip vertebrate cilia, revealing two distinct domains occupied by protein constituents. Using frog, mouse, human MCCs, find that largely uncharacterized proteins, Ccdc78 Ccdc33 occupy a specialized region at extreme tip, these are required other including Spef1, Cep104, Eb3. Cccdc33 also independently length regulation cilia. Mechanistically, display robust microtubule-bundling activity both vivo vitro . Thus, reveal previously undefined proteins form key module organizing stabilizing motile MCC. We propose represent potential disease loci ciliopathies.

Language: Английский

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Mutually independent and cilia-independent assembly of IFT-A and IFT-B complexes at mother centriole

Molecular Biology of the Cell, Journal Year: 2025, Volume and Issue: 36(4)

Published: Feb. 28, 2025

The intraflagellar transport (IFT) machinery, containing the IFT-A and IFT-B complexes powered by dynein-2 kinesin-2 motors, is crucial for bidirectional trafficking of ciliary proteins their import/export across transition zone (TZ). Stepwise assembly anterograde IFT trains was proposed previously; that is, complex first forms a TZ-tethered scaffold with sequential incorporation IFT-A, dynein-2, finally kinesin-2. However, also demonstrate distinct localization to basal body/mother centriole. We show IFT-B, are recruited mother centriole independently ciliogenesis. Furthermore, recruitment can occur in absence respectively, independent IFT-B. Expansion microscopy revealed IFT-A/IFT-B pool at body from TZ. conclude mutually ciliogenesis-independent manner before train assembly.

Language: Английский

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Intraflagellar transport trains can switch rails and move along multiple microtubules in intact primary cilia

Proceedings of the National Academy of Sciences, Journal Year: 2025, Volume and Issue: 122(16)

Published: April 18, 2025

Structural homeostasis and proper distributions of signaling molecules in cilia require a constant flow cargoes carried by intraflagellar transport (IFT) trains both anterograde retrograde directions within the thin, long ciliary shafts. In motile cilium framework, nine microtubule doublets same length serve as transportation rails, preferential association to two subtubules prevents collisions among IFT that move opposite directions. However, this mechanism is incompatible with primary structure, where most terminate shafts—only several them reach tip only singlet form. Here, we demonstrate interact without apparent preference. They can switch microtubules, they may simultaneously multiple microtubules facilitate their movement. This architecture makes inevitable, live-cell recordings reveal tend pause when come into direct contact. We also find velocity train’s movement often changes after pause. Thus, motion behaviors are distinctive from those cilia, our data offer an essential foundation for understanding molecule cilia.

Language: Английский

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Cryo-electron tomography: en route to the molecular anatomy of organisms and tissues

Biochemical Society Transactions, Journal Year: 2024, Volume and Issue: unknown

Published: Dec. 6, 2024

Cryo-electron tomography (cryo-ET) has become a key technique for obtaining structures of macromolecular complexes in their native environment, assessing local organization and describing the molecular sociology cell. While microorganisms adherent mammalian cells are common targets studies, appropriate sample preparation data acquisition strategies larger cellular assemblies such as tissues, organoids or small model organisms have only recently sufficiently practical to allow in-depth structural characterization samples situ. These advances include tailored lift-out approaches using focused ion beam (FIB) milling, improved schemes. Consequently, cryo-ET FIB lamellae from large volume can complement ultrastructural analysis with another level information: anatomy. This review highlights recent developments towards anatomy studies cryo-ET, briefly outlines what be expected near future.

Language: Английский

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Intraflagellar transport protein IFT172 contains a C-terminal ubiquitin-binding U-box-like domain involved in ciliary signaling

bioRxiv (Cold Spring Harbor Laboratory), Journal Year: 2024, Volume and Issue: unknown

Published: Nov. 5, 2024

Abstract Intraflagellar transport (IFT) is a fundamental process driving ciliogenesis in most eukaryotic organisms. IFT172, the largest protein of IFT complex, plays crucial role cilium formation and associated with several disease variants causing ciliopathies. While IFT172 tethered to IFT-B complex via its N-terminal domains, function C-terminal domains has remained elusive. Here, we reveal that part interacts IFT-A subunits, providing molecular basis for bridging complexes. We determine crystal structure uncovering conserved U-box-like domain often found E3 ubiquitin ligases. This exhibits ubiquitin-binding properties auto-ubiquitination activity. The activity reduced C1727R patient ciliopathy variant. use CRISPR-engineered RPE-1 cells demonstrate essential stability proper formation. Notably, heterozygous deletion U-box show altered TGFB signaling responses, particularly SMAD2 phosphorylation levels AKT activation. Our findings suggest novel dual both structural support within trains regulation ciliary ubiquitination pathways, new insights into mechanisms underlying IFT172-related

Language: Английский

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