Article
Multidisciplinary Sciences
Sanjoy Paul, Anjon Audhya, Qiang Cui
Summary: The Sar1 GTPase plays a key role in COPII-mediated protein transport by generating membrane curvature on the endoplasmic reticulum. However, the molecular mechanism by which Sar1 is activated and regulates membrane remodeling remains unclear. Using molecular dynamics simulations, we show that Sar1-GTP inserts into the membrane more efficiently and generates higher positive curvature compared to Sar1-GDP. Dimerization of Sar1-GTP further amplifies curvature generation.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Biochemistry & Molecular Biology
Chinta M. Aryal, Nhat Nguyen Bui, Likai Song, Jianjun Pan
Summary: This study investigates the membrane interactions of the helix 0 of amphiphysin (H0-Amph) and endophilin (H0-Endo) and their effects on membrane properties. It was found that H0-Amph reduces lipid mobility, increases membrane polarity, and decreases lipid chain orientational order. H0-Endo acts as a more potent modulator in anionic membranes. Atomic force microscopy revealed membrane structural changes induced by both peptides, with only H0-Amph inducing membrane fusion. These findings contribute to our understanding of membrane curvature regulation mechanisms.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES
(2022)
Article
Chemistry, Multidisciplinary
Xiangyang Guo, Jan Steinkuehler, Mariana Marin, Xiang Li, Wuyuan Lu, Rumiana Dimova, Gregory B. Melikyan
Summary: IFITM3 inhibits the transition from hemifusion to full fusion by inducing negative membrane curvature and increasing membrane order and stiffness, thus blocking the entry of diverse enveloped viruses.
Article
Biochemistry & Molecular Biology
Kazuma Shimanaka, Bryan Shi, Lisa Brontesi, Heba Alnakhala, Vidyashree Jayanthi, Kanagaraj Subramanian, Nagendran Ramalingam, Arati Tripathi, Ulf Dettmer
Summary: This study reveals the significance of amino acid composition in alpha-synuclein for its interaction with cellular membranes and phosphorylation, providing insights into the biology of alpha-synuclein in health and disease.
Article
Chemistry, Multidisciplinary
Hyun-Soo Kim, Yeongju Lee, Min Hyeon Shin, Hyun-Suk Lim
Summary: The study describes the design, synthesis, and biological evaluation of cell-penetrating, amphipathic cyclic peptoids as an innovative class of molecular transporters. The cyclic peptoids show significantly improved intracellular delivery capability compared to traditional polyarginine cell-penetrating peptides, making them one of the best molecular transporters reported to date. With excellent cell-permeability, proteolytic stability, and ease of synthesis, the amphipathic cyclic peptoids have broad potential for clinical and biological applications.
CHEMICAL COMMUNICATIONS
(2021)
Article
Virology
Kay-Marcus Oetter, Juliane Kuhn, Gregor Meyers
Summary: The pestivirus envelope protein E-rns is anchored in membranes via a long amphipathic helix, and is cleaved from the glycoprotein E1 by cellular signal peptidase. Mutations in charged residues of the membrane anchor affect processing at the E-rns carboxy-terminus, but restoring salt bridges does not necessarily restore processing efficiency. These mutations also enhance E-rns secretion, with varying effects on processing and secretion efficiency. Some mutations in the viral genome impact virus recovery, while others are stable and neutral for virus growth.
Article
Biochemistry & Molecular Biology
Chen-Xi Zou, Zhu-Hui Ma, Zhao-Di Jiang, Zhao-Qian Pan, Dan-Dan Xu, Fang Suo, Guang-Can Shao, Meng-Qiu Dong, Li-Lin Du, Sharon A. Tooze, Richard Hodge, Richard Hodge, Richard Hodge, Richard Hodge
Summary: This study reveals the requirement of a conserved ER-shaping protein for ER-phagy and nucleophagy processes in yeast. Lack of this protein leads to the accumulation of cargo structures (not enclosed within autophagosomes) in the cytoplasm.
Review
Biochemistry & Molecular Biology
Sharon A. Tooze, Wenxin Zhang, Gianmarco Lazzeri, Deepanshi Gahlot, Lipi Thukral, Roberto Covino, Taki Nishimura
Summary: Autophagy is a crucial intracellular pathway for the survival of all eukaryotes. It removes damaged components from cells, ranging from unfolded proteins to entire mitochondria. ATG proteins are essential for the formation and capture of autophagosomes, and recent studies have highlighted the importance of small membrane-associated domains in these proteins. Specifically, the role of α-helical structures in the ATG8 conjugation machinery and ATG8s has been unexpectedly revealed. These findings demonstrate how unique membrane association modules can regulate autophagosome formation.
Article
Biochemistry & Molecular Biology
Anais Vlieghe, Kristina Niort, Hugo Fumat, Jean-Michel Guigner, Mickael M. Cohen, David Tareste
Summary: Mitochondrial fusion is crucial for maintaining the shape, distribution, and function of mitochondria. This study found that phosphatidylethanolamine (PE) and phosphatidic acid (PA) in the mitochondrial membrane effectively stimulate fusion, while cardiolipin (CL) has a slight inhibitory effect. The interplay between divalent cations and specific cone-shaped lipids creates a favorable environment for fusion.
Article
Biochemistry & Molecular Biology
Carolyn J. Decker, James M. Burke, Patrick K. Mulvaney, Roy Parker
Summary: This study shows that the degradation of RNA components has a significant impact on the majority of RNP granules, including SGs, Cajal bodies, nuclear speckles, and the nucleolus, highlighting the critical and widespread role of RNA in the organization of these organelles. PBs and super-enhancer complexes, on the other hand, are largely unaffected by RNA degradation, suggesting a different mechanism of organization for these structures.
Review
Cell Biology
Mohamed Hamed, Wolfram Antonin
Summary: Nuclear pore complexes mediate selective and efficient transport between the cytoplasm and the nucleus, with a complex structure involving transmembrane proteins and nucleoporins interacting with membrane. These protein interactions play a crucial role in NPC assembly, stability, function, and membrane shaping.
Editorial Material
Cell Biology
Taki Nishimura, Gianmarco Lazzeri, Sharon A. Tooze, Roberto Covino
Summary: In our study, we have discovered that ATG3 exhibits dynamic structural changes on autophagic membranes, allowing for efficient LC3 lipidation. The presence of an amphipathic alpha-helix with bulky and hydrophobic residues enables transient membrane association and facilitates enzymatic reaction of ATG3. This research provides insights into the understanding of how ATG proteins interact with membranes during autophagosome formation.
Article
Biochemical Research Methods
Shi-Hao Feng, Chun-Qiu Xia, Pei-Dong Zhang, Hong-Bin Shen
Summary: In this study, a new deep learning-based prediction model is reported, which accurately predicts the structure of amphipathic helix with high interpretability and generalizability.
IEEE-ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS
(2022)
Article
Chemistry, Multidisciplinary
Kazuki Sato, Tomohiro Umeno, Atsushi Ueda, Takuma Kato, Mitsunobu Doi, Masakazu Tanaka
Summary: The N-terminal thiourea-modified l-Leu-based peptide catalyst demonstrated high enantioselectivity in the 1,4-addition reaction, requiring only a small amount for efficient reaction under different substrate and donor conditions.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Virology
Xue Jiang, Yameng Luan, Mengzhu Chai, Yingshuai Yang, Yuting Wang, Wenjia Deng, Yonggang Li, Xiaofei Cheng, Xiaoyun Wu
Summary: This study reveals the association mechanism and multimerization process of RNA-dependent RNA polymerase with endoplasmic reticulum during the replication of potato virus X.