Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves. The PCM comprises hundreds proteins, and there is much debate about its physical nature. Here, we show that Drosophila Spd-2 (human CEP192) fluxes out from centrioles, recruiting Polo Aurora A kinases to catalyze the assembly two distinct mitotic-PCM scaffolds: a Polo-dependent Cnn scaffold, an A-dependent TACC which exhibit solid- liquid-like behaviors, respectively. Both...

Gram-negative bacteria commonly interact with eukaryotic host cells by using type III secretion systems (TTSSs or secretons). TTSSs serve to transfer bacterial proteins into cells. Two translocators, IpaB and IpaC, are first inserted the aid of IpaD Shigella cell membrane. Then at least two supplementary effectors invasion, IpaA IpgD, transferred cytoplasm. How induced secrete is unknown, but their activation appears require direct contact external distal tip apparatus cell. The...

Centrioles are highly structured organelles whose size is remarkably consistent within any given cell type. New centrioles born when Polo-like kinase 4 (Plk4) recruits Ana2/STIL and Sas-6 to the side of an existing “mother” centriole. These two proteins then assemble into a cartwheel, which grows outwards form structural core new daughter. Here, we show that in early Drosophila melanogaster embryos, daughter grow at linear rate during S-phase abruptly stop growing they reach their correct...

The production, manipulation and rescue of a bacterial artificial chromosome clone Vaccinia virus (VAC-BAC) in order to expedite construction expression vectors mutagenesis the genome has been described (Domi & Moss, 2002, PNAS 99 12415–20). genomic BAC was 'rescued' back infectious using Fowlpox helper supply transcriptional machinery. We apply here similar approach attenuated strain Modified Ankara (MVA), now widely used as safe non-replicating recombinant vaccine vector mammals, including...

CP110 is a conserved centriole protein implicated in the regulation of cell division, duplication, and length suppression ciliogenesis. Surprisingly, we report that mutant flies lacking (CP110Δ) were viable fertile had no obvious defects or cilia formation. We show has at least three functions flies. First, it subtly influences by counteracting centriole-elongating activity several duplication proteins. Specifically, centrioles are ∼10% longer than normal CP110Δ mutants ∼20% shorter when...

Centrosomes are formed when mother centrioles recruit pericentriolar material (PCM) around themselves. The PCM expands dramatically as cells prepare to enter mitosis (a process termed centrosome maturation), but it is unclear how this expansion achieved. In flies, Spd-2 and Cnn thought form a scaffold the centriole that recruits other components of mitotic PCM, Polo-dependent phosphorylation at crucial for assembly. Here, we show that, like Cnn, specifically phosphorylated centrosomes. This...

The accurate timing and execution of organelle biogenesis is crucial for cell physiology. Centriole regulated by Polo-like kinase 4 (Plk4) initiates in S-phase when a daughter centriole grows from the side pre-existing mother. Here, we show that Plk4 oscillation at base growing times to ensure centrioles grow right time size. normally entrained cell-cycle oscillator but can run autonomously it-potentially explaining why duplicate independently progression. Mathematical modeling indicates be...

Article3 May 2022Open Access Transparent process Centrioles generate a local pulse of Polo/PLK1 activity to initiate mitotic centrosome assembly Siu-Shing Wong orcid.org/0000-0002-5327-8466 Sir William Dunn School Pathology, University Oxford, UK Contribution: Conceptualization, Data curation, Software, Formal analysis, ​Investigation, Visualization, Writing - original draft, review & editing Search for more papers by this author Zachary M Wilmott orcid.org/0000-0001-6053-9874 Mathematical...

Abstract Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves. In early C. elegans embryos, mitotic centrosome size appears to be set by the limiting amount a key component. Drosophila syncytial thousands are assembled as embryo proceeds through 13 rounds rapid nuclear division, driven core cell cycle oscillator. These divisions slow during cycles 11–13, and we find that respond reciprocally decreasing their growth rate, but...

Centrosomes form when centrioles assemble pericentriolar material (PCM) around themselves. Spd-2/CEP192 proteins, defined by a conserved “Spd-2 domain” (SP2D) comprising two closely spaced AspM-Spd-2-Hydin (ASH) domains, play critical role in centrosome assembly. Here, we show that the SP2D does not target Drosophila Spd-2 to centrosomes but rather promotes PCM scaffold Crystal structures of human and honeybee reveal an unusual “extended cradle” structure mediated interaction interface...

Centrioles organise centrosomes and cilia, these organelles have an important role in many cell processes. In flies, the centriole protein Ana1 is required for assembly of functional cilia. It has recently been shown that Cep135 (also known as Bld10) initially recruits to newly formed centrioles, then Asl (known Cep152 mammals) promote conversion centrioles into centrosomes. Here, we show ana1 mutants lack detectable vivo, irreversibly incorporated during their appears play a more...

Type III secretion systems (T3SSs) are key determinants of virulence in many Gram-negative bacterial pathogens. Upon cell contact, they inject effector proteins directly into eukaryotic cells through a needle protruding from the surface. Host sensing occurs distal "tip complex," but how this is not understood. The tip complex quiescent needles composed IpaD, which topped by IpaB. Physical contact with host initiates and leads to assembly pore, formed IpaB IpaC, membrane, other may be...

ABSTRACT Polo kinase (PLK1 in mammals) is a master cell cycle regulator that recruited to various subcellular structures, often by its polo-box domain (PBD), which binds phosphorylated S-pS/pT motifs. Polo/PLK1 kinases have multiple functions at centrioles and centrosomes, we previously shown Drosophila Sas-4 initiates recruitment newly formed centrioles, while Spd-2 recruits the pericentriolar material (PCM) assembles around mother mitosis. Here, show Ana1 (Cep295 humans) also helps recruit...

Pericentrin is a conserved centrosomal protein whose dysfunction has been linked to several human diseases. It implicated in many aspects of centrosome and cilia function, but its precise role unclear. Here, we examine Drosophila Pericentrin-like-protein (PLP) function vivo tissues that form both centrosomes cilia. Plp mutant centrioles exhibit four major defects: (1) They are short have subtle structural abnormalities; (2) disengage prematurely, so overduplicate; (3) organise fewer...

Centrioles are composed of a central cartwheel tethered to nine-fold symmetric microtubule (MT) blades. The centriole and MTs thought grow from opposite ends these organelles, so it is unclear how they coordinate their assembly. We previously showed that in Drosophila embryos an oscillation Polo-like kinase 4 (Plk4) helps initiate time the growth at proximal end. Here, same model, we show CP110 Cep97 form complex close distal-end whose levels rise fall as new grow, manner appears be...

Centrioles duplicate once per cell cycle, but it is unclear how daughter centrioles assemble at the right time and place grow to size. Here, we show that in Drosophila embryos cytoplasmic concentrations of key centriole assembly proteins Asl, Plk4, Ana2, Sas-6, Sas-4 are low, remain constant throughout process—indicating none them limiting for assembly. The diffusion rate Ana2/STIL, however, increased significantly toward end S-phase as Cdk/Cyclin activity embryo increased. A mutant form...

Abstract Mitotic centrosomes form when centrioles recruit large amounts of pericentriolar material (PCM) around themselves. The PCM comprises hundreds proteins, yet it can assemble and disassemble within minutes, leading to much debate about its physical nature. Here we show that Drosophila Spd-2 fluxes out from centrioles, recruiting Polo Aurora A catalyse the assembly a solid-like Cnn-scaffold more liquid-like TACC-scaffold, respectively. Both scaffolds proteins independently, but both are...

T cells play a central role in the immune response to many of world’s major infectious diseases. In this study we investigated tumour necrosis factor receptor superfamily costimulatory molecule, 4-1BBL (CD137L, TNFSF9), for its ability increase cell immunogenicity induced by variety recombinant vectored vaccines. To efficiently test hypothesis, assessed number promoters and developed stable bi-cistronic vector expressing both antigen adjuvant. Co-expression 4-1BBL, together with our model...

Abstract Mitotic centrosomes are formed when centrioles start to recruit large amounts of pericentriolar material (PCM) around themselves in preparation for mitosis. This centrosome “maturation” requires the and also Polo/PLK1 protein kinase. The PCM comprises several hundred proteins and, Drosophila , Polo cooperates with conserved Spd-2/CEP192 Cnn/CDK5RAP2 assemble a scaffold mother centriole that then recruits other client proteins. We show here syncytial blastoderm embryos, centrosomal...

Abstract The accurate timing of organelle biogenesis and the precise regulation size are crucial for cell physiology. Centriole initiates exclusively in S-phase, when a daughter centriole emerges from side pre-existing mother grows until it reaches its mother’s size. This process is regulated by Polo-like kinase 4 (Plk4), which recruited to centrioles oscillatory waves flies human cells 1,2 . nature function Plk4 oscillations is, however, unknown. Here we discover that forms an adaptive...

Summary Centrioles are composed of a central cartwheel tethered to nine-fold symmetric microtubule (MT) blades. The centriole and MTs thought grow from opposite ends these organelles, so it is unclear how they coordinate their assembly. We previously showed that an oscillation Polo-like kinase 4 (Plk4) helps initiate time the growth at proximal end. Here, we show CP110 Cep97 form complex close distal-end whose levels rise fall as new grow, entrained by core Cdk/Cyclin oscillator drives...

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Abstract Mitotic centrosomes assemble when centrioles recruit large amounts of pericentriolar material (PCM) around themselves in preparation for cell division. How the mitotic PCM grows to correct size is unclear. In Drosophila syncytial embryos, thousands a common cytoplasm as embryo proceeds through 13 rounds near-synchronous nuclear During cycles (NCs) 11-13 these divisions gradually slow, and we find that respond by reciprocally slowing their growth rate increasing period so they grow...