Biological ChemistryPub Date : 2023-05-05Print Date: 2023-07-26DOI: 10.1515/hsz-2023-0126
Lisa Marquardt, Michael Thumm
{"title":"Autophagic and non-autophagic functions of the <i>Saccharomyces cerevisiae</i> PROPPINs Atg18, Atg21 and Hsv2.","authors":"Lisa Marquardt, Michael Thumm","doi":"10.1515/hsz-2023-0126","DOIUrl":"10.1515/hsz-2023-0126","url":null,"abstract":"<p><p>Atg18, Atg21 and Hsv2 are homologous β-propeller proteins binding to PI3P and PI(3,5)P<sub>2</sub>. Atg18 is thought to organize lipid transferring protein complexes at contact sites of the growing autophagosome (phagophore) with both the ER and the vacuole. Atg21 is restricted to the vacuole phagophore contact, where it organizes part of the Atg8-lipidation machinery. The role of Hsv2 is less understood, it partly affects micronucleophagy. Atg18 is further involved in regulation of PI(3,5)P<sub>2</sub> synthesis. Recently, a novel Atg18-retromer complex and its role in vacuole homeostasis and membrane fission was uncovered.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 8-9","pages":"813-819"},"PeriodicalIF":3.7,"publicationDate":"2023-05-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"10536733","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Determinants of synergistic cell-cell interactions in bacteria.","authors":"Benedikt Pauli, Shiksha Ajmera, Christian Kost","doi":"10.1515/hsz-2022-0303","DOIUrl":"https://doi.org/10.1515/hsz-2022-0303","url":null,"abstract":"<p><p>Bacteria are ubiquitous and colonize virtually every conceivable habitat on earth. To achieve this, bacteria require different metabolites and biochemical capabilities. Rather than trying to produce all of the needed materials by themselves, bacteria have evolved a range of synergistic interactions, in which they exchange different commodities with other members of their local community. While it is widely acknowledged that synergistic interactions are key to the ecology of both individual bacteria and entire microbial communities, the factors determining their establishment remain poorly understood. Here we provide a comprehensive overview over our current knowledge on the determinants of positive cell-cell interactions among bacteria. Taking a holistic approach, we review the literature on the molecular mechanisms bacteria use to transfer commodities between bacterial cells and discuss to which extent these mechanisms favour or constrain the successful establishment of synergistic cell-cell interactions. In addition, we analyse how these different processes affect the specificity among interaction partners. By drawing together evidence from different disciplines that study the focal question on different levels of organisation, this work not only summarizes the state of the art in this exciting field of research, but also identifies new avenues for future research.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"521-534"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9367807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"<i>Drosophila</i> collagens in specialised extracellular matrices.","authors":"Marcel Reinhardt, Maik Drechsler, Achim Paululat","doi":"10.1515/hsz-2022-0297","DOIUrl":"https://doi.org/10.1515/hsz-2022-0297","url":null,"abstract":"<p><p>The basement membrane (BM) constitutes a specialised form of the extracellular matrix (ECM) and plays important roles in many biological processes, such as cell migration, organ and tissue integrity, cell polarity, and the formation of metastases. In metazoans, a canonical BM is formed by only a few conserved structural core proteins: Laminin, Collagen IV, Nidogen and Perlecan. Depending on the tissue's function and mechanical load, additional matrix proteins interact with, or are incorporated into the BM, resulting in tissue-specific mechanical properties, such as higher stiffness or elasticity, or special resistance to mechanical stress or harmful environmental conditions. In flies, the collagen IV-like protein Pericardin forms an integral constituent of matrices around the heart and tension sensors (chordotonal organs) of the peripheral nervous system. The function and integrity of both organ systems strongly relies on the appropriate establishment of a Pericardin (Prc) matrix and the function of its adapter protein-Lonely heart (Loh). In this review, we provide an overview of the four collagens present in flies, and will discuss our recent work on the formation and function of Pericardin-containing matrices, the role of the adapter protein Lonely heart and the necessity of specialised ECM molecules in tissue architecture and function.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"535-550"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9312886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniel Kümmel, Eric Herrmann, Lars Langemeyer, Christian Ungermann
{"title":"Molecular insights into endolysosomal microcompartment formation and maintenance.","authors":"Daniel Kümmel, Eric Herrmann, Lars Langemeyer, Christian Ungermann","doi":"10.1515/hsz-2022-0294","DOIUrl":"https://doi.org/10.1515/hsz-2022-0294","url":null,"abstract":"<p><p>The endolysosomal system of eukaryotic cells has a key role in the homeostasis of the plasma membrane, in signaling and nutrient uptake, and is abused by viruses and pathogens for entry. Endocytosis of plasma membrane proteins results in vesicles, which fuse with the early endosome. If destined for lysosomal degradation, these proteins are packaged into intraluminal vesicles, converting an early endosome to a late endosome, which finally fuses with the lysosome. Each of these organelles has a unique membrane surface composition, which can form segmented membrane microcompartments by membrane contact sites or fission proteins. Furthermore, these organelles are in continuous exchange due to fission and fusion events. The underlying machinery, which maintains organelle identity along the pathway, is regulated by signaling processes. Here, we will focus on the Rab5 and Rab7 GTPases of early and late endosomes. As molecular switches, Rabs depend on activating guanine nucleotide exchange factors (GEFs). Over the last years, we characterized the Rab7 GEF, the Mon1-Ccz1 (MC1) complex, and key Rab7 effectors, the HOPS complex and retromer. Structural and functional analyses of these complexes lead to a molecular understanding of their function in the context of organelle biogenesis.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"441-454"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9316827","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Caroline Barisch, Joost C M Holthuis, Katia Cosentino
{"title":"Membrane damage and repair: a thin line between life and death.","authors":"Caroline Barisch, Joost C M Holthuis, Katia Cosentino","doi":"10.1515/hsz-2022-0321","DOIUrl":"https://doi.org/10.1515/hsz-2022-0321","url":null,"abstract":"<p><p>Bilayered membranes separate cells from their surroundings and form boundaries between intracellular organelles and the cytosol. Gated transport of solutes across membranes enables cells to establish vital ion gradients and a sophisticated metabolic network. However, an advanced compartmentalization of biochemical reactions makes cells also particularly vulnerable to membrane damage inflicted by pathogens, chemicals, inflammatory responses or mechanical stress. To avoid potentially lethal consequences of membrane injuries, cells continuously monitor the structural integrity of their membranes and readily activate appropriate pathways to plug, patch, engulf or shed the damaged membrane area. Here, we review recent insights into the cellular mechanisms that underly an effective maintenance of membrane integrity. We discuss how cells respond to membrane lesions caused by bacterial toxins and endogenous pore-forming proteins, with a primary focus on the intimate crosstalk between membrane proteins and lipids during wound formation, detection and elimination. We also discuss how a delicate balance between membrane damage and repair determines cell fate upon bacterial infection or activation of pro-inflammatory cell death pathways.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"467-490"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9317876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Neprilysin 4: an essential peptidase with multifaceted physiological relevance.","authors":"Annika Buhr, Ronja Schiemann, Heiko Meyer","doi":"10.1515/hsz-2022-0286","DOIUrl":"https://doi.org/10.1515/hsz-2022-0286","url":null,"abstract":"<p><p>Neprilysins are highly conserved ectoenzymes that hydrolyze and thus inactivate signaling peptides in the extracellular space. Herein, we focus on Neprilysin 4 from <i>Drosophila melanogaster</i> and evaluate the existing knowledge on the physiological relevance of the peptidase. Particular attention is paid to the role of the neprilysin in regulating feeding behavior and the expression of insulin-like peptides in the central nervous system. In addition, we assess the function of the peptidase in controlling the activity of the sarcoplasmic and endoplasmic reticulum Ca<sup>2+</sup> ATPase in myocytes, as well as the underlying molecular mechanism in detail.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"513-520"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9317341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Highlight: on the past and the future of cellular microcompartments.","authors":"Milos Galic, Christian Ungermann, Katia Cosentino","doi":"10.1515/hsz-2023-0153","DOIUrl":"https://doi.org/10.1515/hsz-2023-0153","url":null,"abstract":"","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"377-378"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9307013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Computational resolution in single molecule localization - impact of noise level and emitter density.","authors":"Mathias Hockmann, Stefan Kunis, Rainer Kurre","doi":"10.1515/hsz-2022-0301","DOIUrl":"https://doi.org/10.1515/hsz-2022-0301","url":null,"abstract":"<p><p>Classical fluorescence microscopy is a powerful technique to image biological specimen under close-to-native conditions, but light diffraction limits its optical resolution to 200-300 nm-two orders of magnitude worse than the size of biomolecules. Assuming single fluorescent emitters, the final image of the optical system can be described by a convolution with the point spread function (PSF) smearing out details below the size of the PSF. In mathematical terms, fluorescence microscopy produces bandlimited space-continuous images that can be recovered from their spatial samples under the conditions of the classical Shannon-Nyquist theorem. During the past two decades, several single molecule localization techniques have been established and these allow for the determination of molecular positions with sub-pixel accuracy. Without noise, single emitter positions can be recovered precisely - no matter how close they are. We review recent work on the computational resolution limit with a sharp phase transition between two scenarios: 1) where emitters are well-separated with respect to the bandlimit and can be recovered up to the noise level and 2) closely distributed emitters which results in a strong noise amplification in the worst case. We close by discussing additional pitfalls using single molecule localization techniques based on structured illumination.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"427-431"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9367349","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"The readily retrievable pool of synaptic vesicles.","authors":"Sai Krishnan, Jürgen Klingauf","doi":"10.1515/hsz-2022-0298","DOIUrl":"https://doi.org/10.1515/hsz-2022-0298","url":null,"abstract":"<p><p>In the CNS communication between neurons occurs at synapses by secretion of neurotransmitter via exocytosis of synaptic vesicles (SVs) at the active zone. Given the limited number of SVs in presynaptic boutons a fast and efficient recycling of exocytosed membrane and proteins by triggered compensatory endocytosis is required to maintain neurotransmission. Thus, pre-synapses feature a unique tight coupling of exo- and endocytosis in time and space resulting in the reformation of SVs with uniform morphology and well-defined molecular composition. This rapid response requires early stages of endocytosis at the peri-active zone to be well choreographed to ensure reformation of SVs with high fidelity. The pre-synapse can address this challenge by a specialized membrane microcompartment, where a pre-sorted and pre-assembled readily retrievable pool (RRetP) of endocytic membrane patches is formed, consisting of the vesicle cargo, presumably bound within a nucleated Clathrin and adaptor complex. This review considers evidence for the RRetP microcompartment to be the primary organizer of presynaptic triggered compensatory endocytosis.</p>","PeriodicalId":8885,"journal":{"name":"Biological Chemistry","volume":"404 5","pages":"385-397"},"PeriodicalIF":3.7,"publicationDate":"2023-04-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"9305955","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}