Review
Biochemistry & Molecular Biology
Karl Forchhammer, Khaled A. Selim, Luciano F. Huergo
Summary: PII proteins are multitasking information-processing proteins that play important roles in cellular metabolism by regulating nitrogen and carbon metabolism, transporters, signaling molecules, and cofactors. Recent research has discovered new targets of PII proteins through ligand fishing assays and identified a class of PII-interacting proteins that further extend the regulatory range of PII proteins.
TRENDS IN MICROBIOLOGY
(2022)
Article
Microbiology
Gregor L. Weiss, Fabian Eisenstein, Ann-Katrin Kieninger, Jingwei Xu, Hannah A. Minas, Milena Gerber, Miki Feldmueller, Iris Maldener, Karl Forchhammer, Martin Pilhofer
Summary: This study characterized a contractile injection system (CIS) in the multicellular cyanobacterium Anabaena, revealing its unique localization and function. The CISs were found to be anchored in the thylakoid membrane through extensions of tail fibre and baseplate components. Upon stress, cyanobacteria induced the formation of ghost cells, which may be mediated by these CISs and involved in interactions with other organisms. These findings provide insights into the re-engineering of CISs and their potential roles in cyanobacterial programmed cell death.
NATURE MICROBIOLOGY
(2022)
Article
Plant Sciences
Oliver Mantovani, Viktoria Reimann, Michael Haffner, Felix Philipp Herrmann, Khaled A. Selim, Karl Forchhammer, Wolfgang R. Hess, Martin Hagemann
Summary: This study found that SbtB regulates a subset of genes involved in low carbon adaptation in Synechocystis, while c-di-AMP and cAMP have a lesser impact on gene expression under different carbon conditions.
Article
Biology
Ritu Garg, Manja Luckner, Juergen Berger, Katharina Hipp, Gerhard Wanner, Karl Forchhammer, Iris Maldener
Summary: The freshwater cyanobacterium Trichormus variabilis can differentiate into heterocysts and akinetes to survive under different stress conditions. Akinetes have a wrinkled envelope that smoothes out during germination, and the envelope's multilayered architecture helps withstand osmotic stress. Intercommunication decreases during akinete formation but is restored in freshly germinating filaments.
Article
Microbiology
Niels Neumann, Simon Friz, Karl Forchhammer
Summary: Glc-1,6-BP is an essential activator in multiple metabolic processes. This study identifies a new subfamily of α-PHM enzymes that can synthesize Glc-1,6-BP in both cyanobacteria and gut bacteria, indicating the widespread presence and importance of this enzyme activity.
Article
Multidisciplinary Sciences
Raphael Reher, Allegra T. Aron, Pavla Fajtova, Paolo Stincone, Berenike Wagner, Alicia Perez-Lorente, Chenxi Liu, Ido Y. Ben Shalom, Wout Bittremieux, Mingxun Wang, Kyowon Jeong, Marie L. Matos-Hernandez, Kelsey L. Alexander, Eduardo J. Caro-Diaz, C. Benjamin Naman, J. H. William Scanlan, Phil M. M. Hochban, Wibke E. Diederich, Carlos Molina-Santiago, Diego Romero, Khaled A. Selim, Peter Sass, Heike Broetz-Oesterhelt, Chambers C. Hughes, Pieter C. Dorrestein, Anthony J. O'Donoghue, William H. Gerwick, Daniel Petras
Summary: The identity and biological activity of most metabolites are still unknown, and compound purification is a bottleneck for exploring their structures and pharmaceutical activities. Using a scalable native metabolomics approach, we identified a class of potentially bioactive metabolites and conducted structural elucidation and biological activity evaluation.
NATURE COMMUNICATIONS
(2022)
Editorial Material
Nanoscience & Nanotechnology
Amit Srivastava, Khaled A. Selim
NATURE NANOTECHNOLOGY
(2022)
Review
Biotechnology & Applied Microbiology
Piyoosh K. Babele, Amit Srivastava, Khaled A. Selim, Anil Kumar
Summary: The excessive use of nitrogen fertilizers has detrimental effects on the environment. Therefore, developing crop varieties with improved nitrogen use efficiency is necessary. Orphan crops like millets, which are adapted to lower input conditions, can serve as a source of beneficial traits for improving nitrogen use efficiency in major crops. Systems biology can help uncover the enzymes and pathways involved in nitrogen metabolism of millets, contributing to the generation of transgenic crops with improved nitrogen use efficiency.
TRENDS IN BIOTECHNOLOGY
(2023)
Article
Plant Sciences
Tim Rammler, Frank Wackenhut, Johanna Rapp, Sven Zur Oven-Krockhaus, Karl Forchhammer, Alfred J. J. Meixner, Klaus Harter
Summary: Photosynthesis is a vital biological process that produces oxygen and is the foundation for various plant products. Measurement of photosynthetic properties can provide insights into the physiological conditions of organisms. A new method using an optical Fabry-Perot microcavity allows for the assessment of photosynthetic activity and properties for individual cyanobacteria.
Article
Biology
Markus Burkhardt, Johanna Rapp, Claudia Menzel, Hannes Link, Karl Forchhammer
Summary: Dormancy and resuscitation are crucial for bacterial survival. In the absence of nitrogen sources, Synechocystis sp. PCC 6803 enters a metabolically quiescent state called chlorosis, allowing long-term survival. The resuscitation process is highly coordinated and sodium plays a vital role in various aspects, including bioenergetics, nitrogen assimilation, pH regulation, and metabolite synthesis.
Article
Multidisciplinary Sciences
Khaled A. Selim, Michael Haffner, Oliver Mantovani, Reinhard Albrecht, Hongbo Zhu, Martin Hagemann, Karl Forchhammer, Marcus D. Hartmann
Summary: The PII superfamily is a widespread signal transduction proteins found in all domains of life. In addition to canonical PII proteins involved in C/N sensing, structurally similar PII-like proteins evolved to fulfill diverse cellular functions. Cyanobacterial protein SbtB acts as a sensor of various adenine nucleotides and possesses a redox-regulatory function. It has an unusual ATP/ADP apyrase activity controlled by the redox state of the protein. This protein plays a central role in regulating cyanobacterial cell physiology by integrating signals from energy state, carbon supply, and day/night status.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Microbiology
Antonio Llop, Jose I. Labella, Marina Borisova, Karl Forchhammer, Khaled A. Selim, Asuncion Contreras
Summary: The cyanobacterial protein PipY belongs to the PLP-binding proteins family and is involved in the homeostasis of vitamin B-6 vitamers and amino/keto acids. It is connected with PipX in the cyanobacteria genomic context and involved in signaling the intracellular energy status and carbon-to-nitrogen balance. While the function of PipY is still uncertain, preliminary data suggests its involvement in signaling pathways related to the stringent stress response.
FRONTIERS IN MICROBIOLOGY
(2023)