Article
Cell Biology
Claudia Puri, David C. Rubinsztein
Summary: Using superresolution structured illumination microscopy and electron microscopy, researchers have found that mammalian autophagosomes derive from finger-like outgrowths from the recycling endosome. These fingers close into a fist and the openings are sealed in an ESCRT-dependent fashion. The scission of the autophago-dome liberates free autophagosomes from this compartment, revealing unexpected morphologies of autophagosome precursors and raising new questions about the control of this process.
Editorial Material
Cell Biology
Xinyu Gong, Lifeng Pan
Summary: The recruitment of ATG12-ATG5-ATG16L1 complex to phagophore, which is crucial in autophagosome formation, relies on the specific interaction between ATG16L1 and WIPI2. It has been found that ATG16L1 contains two distinct WIPI2-binding sites, WBS1 and the newly identified WBS2, and the binding mechanism between ATG16L1 WBS2 and WIPI2 is conserved across species. The integrity of these two WIPI2-binding sites in ATG16L1 is essential for normal autophagic flux.
Article
Cell Biology
Wei Wan, Wei Liu
Summary: STING interacts directly with WIPI2 to recruit WIPI2 to STING-positive vesicles for LC3 lipidation and autophagosome formation. STING and PtdIns3P competitively bind to the FRRG motif of WIPI2, resulting in mutual inhibition between STING-induced and PtdIns3P-dependent autophagy. Additionally, the STING-WIPI2 interaction is essential for clearing cytoplasmic DNA and attenuating activated cGAS-STING signaling.
Article
Cell Biology
Lydia Wunderley, Ling Zhang, Rebecca Yarwood, Wenxia Qin, Martin Lowe, Philip Woodman
Summary: LITAF and CDIP1 are novel membrane curvature proteins involved in recycling tubule scission. Depletion of both proteins results in expansion of tubular recycling compartments and impaired integrin recycling.
JOURNAL OF CELL SCIENCE
(2021)
Review
Biochemistry & Molecular Biology
Antonio Galindo, Sean Munro
Summary: Transport Protein Particle (TRAPP) complexes are conserved complexes that act as nucleotide exchange factors for Rab GTPases. They play roles in protein secretion, autophagy, and other processes. There are two complexes in metazoans: TRAPPII activates Rab11, and TRAPPIII activates Rab1. Crystal and cryo-EM structures have provided insights into the organization and activation mechanisms of these complexes.
Review
Biology
Elsi Ferro, Carla Bosia, Carlo C. Campa
Summary: The small GTPase RAB11 plays a crucial role in vesicular trafficking and membrane dynamics, affecting the sensory and transduction apparatuses of cancer cells. Targeting RAB11 could be a potential therapeutic strategy to inhibit the acquisition of aggressive traits by cancer cells, as alterations in RAB11 significantly impact cell physiology and cancer progression.
Review
Biochemistry & Molecular Biology
Kristian Prydz, Jaakko Saraste
Summary: There is significant interest in understanding the life cycle of SARS-CoV-2 and identifying potential targets for drug intervention. Although the exact mechanisms of how the virus is released from host cells are still unclear, several possible pathways have been proposed. This article provides an overview of the life cycle of coronaviruses, with a special focus on different routes for virus egress.
MOLECULAR MICROBIOLOGY
(2022)
Review
Virology
Mohd Shariq, Asrar A. Malik, Javaid A. Sheikh, Seyed E. Hasnain, Nasreen Z. Ehtesham
Summary: SARS-CoV-2 blocks autophagosome-lysosome fusion to regulate autophagic flux, leading to accumulation of membranous vesicles. ORF3a plays a significant role in regulating autophagy by forming a complex with UV radiation resistance associated and modulating the functions of lipid kinase complexes, thereby controlling autophagosome biogenesis. ORF3a inhibits autolysosome formation by sequestering VPS39 and preventing assembly of the SNARE complex. ORF3a also promotes reticulophagy, proinflammatory responses, and ER stress by inducing the interaction between BECN1 and HMGB1, activating PIK3CA kinases, and recruits BORCS6 and ARL8B for anterograde transport of the virus.
JOURNAL OF MEDICAL VIROLOGY
(2023)
Review
Cell Biology
Yan Zhen, Harald Stenmark
Summary: Autophagy is a crucial process for cellular homeostasis, involving the degradation of cytoplasmic material through the formation of autophagosomes. Recent research has highlighted the role of vesicles containing ATG9 as potential initiators of autophagosome formation, as well as the involvement of ESCRT proteins in sealing the phagophore.
Article
Neurosciences
Xiaofang Zhao, Yuan Guan, Fengwei Liu, Shuxin Yan, Yalong Wang, Meiqin Hu, Yuhong Li, Rena Li, Claire Xi Zhang
Summary: The cell-to-cell transmission of pathological alpha-synuclein is a critical event in synucleinopathies, and its secretion is shown to be SNARE-dependent and mediated by multiple vesicular pathways.
MOLECULAR NEUROBIOLOGY
(2022)
Review
Neurosciences
Jiajia Zhang, Gang Su, Qionghui Wu, Jifei Liu, Ye Tian, Xiaoyan Liu, Juanping Zhou, Juan Gao, Wei Chen, Deyi Chen, Zhenchang Zhang
Summary: The membrane trafficking process regulated by Rab11 plays a crucial role in the nervous system, maintaining neurological function and promoting nerve regeneration. Abnormal expression of Rab11 is closely related to the transport and clearance of disease-related pathological proteins in various neurodegenerative diseases, and overexpression or increased activity of Rab11 can improve membrane trafficking defects and slow down disease progression.
INTERNATIONAL JOURNAL OF NEUROSCIENCE
(2021)
Article
Cell Biology
Nicholas Ariotti, Yeping Wu, Satomi Okano, Yann Gambin, Jordan Follett, James Rae, Charles Ferguson, Rohan D. Teasdale, Kirill Alexandrov, Frederic A. Meunier, Michelle M. Hill, Robert G. Parton
Summary: CAV1 can be secreted in an inverted form from specific types of prostate cancer cells, and released through a non-canonical autophagy pathway, representing a novel class of exosomes.
Review
Oncology
Pooja Rai, Jagat Kumar Roy
Summary: Neurodegenerative diseases are progressive disorders of the nervous system that primarily involve the loss of neuronal cells in the brain. Certain genes, such as parkin and pink1, are found to play a role in removing damaged mitochondria through a process called autophagy. Autophagy is a critical cellular process involving the endosomal Rab proteins, with Rab11 being involved in autophagosome formation and maturation. Loss of Rab11 can impede the autophagy pathway, leading to cellular apoptosis.
EXPERIMENTAL CELL RESEARCH
(2022)
Article
Oncology
Chenyang Qi, Liping Zou, Suxia Wang, Xing Mao, Yuan Hu, Jiaoyu Shi, Zhigang Zhang, Huijuan Wu
Summary: This study reveals that Vps34 acts as an invasion suppressor in hepatocellular carcinoma (HCC) cells. Vps34 can promote lysosomal juxtanuclear accumulation, leading to a reduction in HCC cell invasion through the Rab7-RILP pathway. Additionally, the deficiency of Vps34 in HCC cells affects the endosome-lysosome system, resulting in enhanced Rab11-mediated endocytic recycling of cell surface receptors and increased HCC cell invasion.
CANCER RESEARCH AND TREATMENT
(2022)
Article
Biochemistry & Molecular Biology
Naava Naslavsky, Steve Caplan
Summary: This Viewpoint focuses on the importance of endosomes in cells and the underlying mechanisms of their functions.