Menu

Close

Dynamin-2 facilitates Atg9 recycling from nascent autophagosomes

Alejandro Martorell Riera, Cinta Iriondo Martinez, Samuel Itskanov, Janos Steffen, Brett Roach, Carla M Koehler, Alexander M Van der Bliek

Preprint posted on January 06, 2018 https://www.biorxiv.org/content/early/2018/01/06/241901

How do our cells get rid of their trash? A recent preprint sheds lights on how proteins that drive autophagosome formation are retrieved from destruction for future use.

Selected by Justin Joachim

Categories: cell biology

Background

Autophagy is an intracellular recycling process that removes damaging material, such as protein aggregates, dysfunctional mitochondria and invading pathogens, for eventual destruction and reuse of the constituent components. As such, autophagy protects us from diseases, including cancer and neurodegeneration. Autophagy involves the formation of a large vesicle that engulfs cargo for destruction in the lysosome and this is accompanied by the action of a series of autophagy machinery proteins. Atg9 is the only transmembrane protein within the autophagy related genes, and Atg9-containing vesicles are thought to deliver membrane and/or important proteins to the growing autophagosome membrane through ‘kiss and run’ interactions. However, in mammals, Atg9 itself is not incorporated into the autophagosome but is instead recycled. How Atg9 avoids incorporation into the autophagosome and destruction is unknown.

Key findings

The authors of this preprint investigated the role of Dynamin-2 in autophagy. Dynamins are GTPases that mediate membrane scission during the formation of vesicles, most famously during endocytosis. They found that Dynamin-2 colocalises with autophagosome proteins and loss of Dynamin-2 function by means of genetic knockout, siRNA depletion or chemical inhibition increases the colocalisation of Atg9 with autophagosomes. Most interestingly, in the absence of Dynamin-2, Atg9 was re-routed to degradative lysosomes, where it was destroyed. The authors conclude that Dynamin-2 facilitates the removal of Atg9 from the growing autophagosome membrane.

 

“Blocking Atg9 recycling by interfering with Dynamin-2 helps retain Atg9 in autophagosomes and degrades Atg9 by autophagy.”

 

What I like about this work

This study could answer how the poorly understood and core autophagy protein Atg9 is recycled during autophagy for continual use.

Open questions

This work raises some fascinating questions. It would be exciting to see if Dynamin-2 is involved in generating the reservoir of Atg9 vesicles that contribute to autophagosome formation, perhaps derived from endosomes and the Golgi. Are there BAR domain-containing proteins that act in concert with Dynamin-2 at the forming autophagosome? Can our cells run out of Atg9 vesicles if Dynamin-2 is dysfunctional?

Tags: atg9, autophagy, dynamin, membrane trafficking

Posted on: 27th February 2018

Read preprint (No Ratings Yet)




  • Have your say

    Your email address will not be published. Required fields are marked *

    This site uses Akismet to reduce spam. Learn how your comment data is processed.

    Sign up to customise the site to your preferences and to receive alerts

    Register here

    Also in the cell biology category:

    A DNA-based voltmeter for organelles

    Anand Saminathan, John Devany, Kavya S Pillai, et al.



    Selected by Robert Mahen

    Central spindle microtubules are strongly coupled to chromosomes during both anaphase A and anaphase B

    Che-Hang Yu, Stefanie Redemann, Hai-Yin Wu, et al.



    Selected by Federico Pelisch

    1

    Cell growth dilutes the cell cycle inhibitor Rb to trigger cell division

    Evgeny Zatulovskiy, Daniel F. Berenson, Benjamin R. Topacio, et al.



    Selected by Zaki Ahmad

    1

    Minimal membrane interactions conferred by Rheb C-terminal farnesylation are essential for mTORC1 activation

    Shawn M Ferguson, Brittany Angarola



    Selected by Sandra Malmgren Hill

    Mechanical Stretch Kills Transformed Cancer Cells

    Ajay Tijore, Mingxi Yao, Yu-Hsiu Wang, et al.



    Selected by Vibha SINGH

    EHD2-mediated restriction of caveolar dynamics regulates cellular lipid uptake

    Claudia Matthaeus, Ines Lahmann, Severine Kunz, et al.



    Selected by Andreas Müller

    1

    Mechanical Stretch Kills Transformed Cancer Cells

    Ajay Tijore, Mingxi Yao, Yu-Hsiu Wang, et al.



    Selected by Joseph Jose Thottacherry

    Inactive USP14 and inactive UCHL5 cause accumulation of distinct ubiquitinated proteins in mammalian cells

    Jayashree Chadchankar, Victoria Korboukh, Peter Doig, et al.



    Selected by Mila Basic

    A metabolic switch from OXPHOS to glycolysis is essential for cardiomyocyte proliferation in the regenerating heart

    Hessel Honkoop, Dennis de Bakker, Alla Aharonov, et al.



    Selected by Andreas van Impel

    1

    S-acylated Golga7b stabilises DHHC5 at the plasma membrane to regulate desmosome assembly and cell adhesion.

    Keith T Woodley, Mark O Collins



    Selected by Abagael Lasseigne

    3

    A complex containing lysine-acetylated actin inhibits the formin INF2

    Mu A, Tak Shun Fung, Arminja N. Kettenbach, et al.



    Selected by Laura McCormick

    1

    Super-resolution Molecular Map of Basal Foot Reveals Novel Cilium in Airway Multiciliated Cells

    Quynh Nguyen, Zhen Liu, Rashmi Nanjundappa, et al.



    Selected by Robert Mahen

    Single cell RNA-Seq reveals distinct stem cell populations that drive sensory hair cell regeneration in response to loss of Fgf and Notch signaling

    Mark E. Lush, Daniel C. Diaz, Nina Koenecke, et al.

    AND

    Distinct progenitor populations mediate regeneration in the zebrafish lateral line.

    Eric D Thomas, David Raible



    Selected by Rudra Nayan Das

    1

    Actomyosin-II facilitates long-range retrograde transport of large cargoes by controlling axonal radial contractility

    Tong Wang, Wei Li, Sally Martin, et al.



    Selected by Ivana Viktorinová

    Atlas of Subcellular RNA Localization Revealed by APEX-seq

    Furqan M Fazal, Shuo Han, Pornchai Kaewsapsak, et al.

    AND

    Proximity RNA labeling by APEX-Seq Reveals the Organization of Translation Initiation Complexes and Repressive RNA Granules

    Alejandro Padron, Shintaro Iwasaki, Nicholas Ingolia



    Selected by Christian Bates

    Applications, Promises, and Pitfalls of Deep Learning for Fluorescence Image Reconstruction

    Chinmay Belthangady , Loic A. Royer



    Selected by Romain F. Laine
    Close