A perinuclear microtubule-organizing center controls nuclear positioning and basement membrane secretion

Abstract Non-centrosomal microtubule-organizing centers (ncMTOCs) have a variety of roles presumed to serve the diverse functions of the range of cell types in which they are found. ncMTOCs are diverse in their composition, subcellular localization, and function. Here we report a novel perinuclear MTOC inDrosophilafat body cells that is anchored by Msp300/Nesprin at the cytoplasmic surface of the nucleus. Msp300 recruits the MT minus-end protein Patronin/CAMSAP, which functions redundantly with Ninein to further recruit the MT polymerase Msps/XMAP215 to assemble non-centrosomal MTs and does so independently of the widespread MT nucleation factorγ-tubulin. Functionally, the fat body ncMTOC and the radial MT arrays it organizes is essential for nuclear positioning and for secretion of basement membrane components via retrograde dynein-dependent endosomal trafficking that restricts plasma membrane growth. Together, this study identifies a perinuclear ncMTOC with unique architecture and MT regulation properties that serves vital functions.Highlights <jats:list list-type="bullet">A novel perinuclear MTOC in differentiated fat body cellsThe predominant nucleator,γ-tubulin, is not required at the fat body ncMTOCMsp300/Nesprin organizes the ncMTOC at the nuclear surface by recruiting Patronin/CAMSAP and the spectraplakin ShotPatronin cooperates with Ninein to control MT assembly at the fat body ncMTOC by recruiting MspsMsps, a MT polymerase, is essential for radial MT elongation from the fat body ncMTOCPatronin and Msps associateThe ncMTOC and radial MTs, but not actin, control nuclear positioning in the fat bodyThe fat body MTOC controls retrograde endocytic trafficking to regulate plasma membrane growth and secretion of basement membrane proteins<jats:fig id="ufig1" position="float" orientation="portrait" fig-type="figure"><jats:graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="888065v1_ufig1" position="float" orientation="portrait" /></jats:fig>.

Medienart:

Preprint

Erscheinungsjahr:

2022

Erschienen:

2022

Enthalten in:

bioRxiv.org - (2022) vom: 09. Okt. Zur Gesamtaufnahme - year:2022

Sprache:

Englisch

Beteiligte Personen:

Zheng, Yiming [VerfasserIn]
Buchwalter, Rebecca A. [VerfasserIn]
Zheng, Chunfeng [VerfasserIn]
Wight, Elise M. [VerfasserIn]
Chen, Jieyan V. [VerfasserIn]
Megraw, Timothy L. [VerfasserIn]

Links:

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Themen:

570
Biology

doi:

10.1101/2019.12.24.888065

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

XBI000688371