Biophysics

Characterization and modulation of human insulin degrading enzyme conformational dynamics to control enzyme activity

1. Jordan M Mancl
2. Wenguang G Liang
3. Nicholas L Bayhi
4. Hui Wei
5. William Budell
6. Joshua H Mendez
7. Tobin R Sosnick
8. Bridget Carragher
9. Clinton S Potter
10. Wei-Jen Tang

• Curated by eLife

  eLife Assessment

  The manuscript by Mancl et al. provides important mechanistic insights into the conformational dynamics of Insulin Degrading Enzyme (IDE), a zinc metalloprotease involved in the clearance of amyloid peptides. In the revised version, the authors have substantially expanded their analysis by incorporating time-resolved cryo-EM and coarse-grained molecular dynamics simulations, which reveal an insulin-induced allosteric transition and transient β-sheet interactions underlying IDE's unfoldase activity. Supported by a convincing combination of cryo-EM, SEC-SAXS, enzymatic assays, and both all-atom and coarse-grained simulations, this work refines our understanding of IDE's functional cycle and offers a structural framework for developing substrate-selective modulators of M16 metalloproteases.

Reviewed by eLife

Multi-barrier unfolding of the double-knotted protein, TrmD–Tm1570, revealed by single-molecule force spectroscopy and molecular dynamics

1. Fernando Bruno da Silva
2. Szymon Niewieczerzal
3. Iwona Lewandowska
4. Mateusz Fortunka
5. Maciej Sikora
6. Laura-Marie Silbermann
7. Katarzyna Tych
8. Joanna I Sulkowska

• Curated by eLife

  eLife Assessment

  This study investigates the folding and unfolding behavior of the doubly knotted protein TrmD-Tm1570, providing insight into the molecular mechanisms underlying protein knotting. The findings reveal multiple unfolding pathways and suggest that the formation of double knots may require chaperone assistance, offering valuable insights into topologically complex proteins. The evidence is solid, supported by consistent agreement between simulation and experiment, though some aspects of the presentation and experimental scope could be clarified or expanded.

Reviewed by eLife

Atypical collective oscillatory activity in cardiac tissue uncovered by optogenetics

1. Alexander S Teplenin
2. Nina N Kudryashova
3. Rupamanjari Majumder
4. Antoine AF de Vries
5. Alexander V Panfilov
6. Daniël A Pijnappels
7. Tim De Coster

• Curated by eLife

  eLife Assessment

  This important work provides mechanistic insights into the development of cardiac arrhythmia and establishes a new experimental use case for optogenetics in studying cardiac electrophysiology. The agreement between computational models and experimental observations provides a convincing level of evidence that wave train-induced pacemaker activity can originate in continuously depolarized tissue, with the limitation that there may be differences between depolarization arising from constant optogenetic stimulation, as opposed to pathophysiological tissue depolarization. Future experiments in vivo and in other tissue preparations would extend the generality of these findings.

Reviewed by eLife

Protein-Induced Membrane Strain Drives Supercomplex Formation

1. Maximilian C Pöverlein
2. Alexander Jussupow
3. Hyunho Kim
4. Ville RI Kaila

• Curated by eLife

  eLife Assessment

  In this important study, the authors conducted extensive atomistic and coarse-grained simulations as well as a lattice Monte Carlo analysis to probe the driving force and functional impact of supercomplex formation in the inner mitochondrial membrane. The study highlighted the major contribution from membrane mechanics to the supercomplex formation and revealed interesting differences in structural and dynamical features of the protein components upon complex formation. Upon revision, the analysis is considered solid, although the magnitude of estimated membrane deformation energies seem somewhat large. Overall, the study is thorough, creative and the impact on the field of bioenergetics is expected to be significant.

Reviewed by eLife

DNA tensiometer reveals catch-bond detachment kinetics of kinesin-1, -2 and -3

1. Crystal R Noell
2. Tzu-Chen Ma
3. Rui Jiang
4. Scott A McKinley
5. William O Hancock

• Curated by eLife

  eLife Assessment

  The use of DNA tethers is an important advance for studying how motor proteins respond to load. The authors use a convincing methodology to investigate the detachment and reattachment kinetics of kinesin-1, 2, and 3 motors against loads oriented parallel to the microtubule. As the manuscript stands, the conclusions drawn from the experiments, as well as the overall interpretation of the results, are incompletely supported by the presented data, and the novelty over previous reports appears less clear.

Reviewed by eLife

Enhanced Processivity and Collective Force Production of Kinesins at Low Radial Forces

1. Andrew M Hensley
2. Ahmet Yildiz

• Curated by eLife

  eLife Assessment

  The manuscript by Hensley and Yildez studies the mechanical behavior of kinesin under conditions where the z-component of the applied force is minimized. The important study shows that much of the mechanical information gleaned from the traditional "one bead" with attached kinesin approach was probably profoundly influenced by the direction of the applied force. The data are convincing, but in some cases the amount of data collected appears to be smaller than optimal.

Reviewed by eLife

Non-Invasive Mechanical-Functional Analysis of Individual Liver Mitochondria by Atomic Force Microscopy

1. Ekaterina O. Zorikova
2. Sabita Chourasia
3. Irit Rosenhek-Goldian
4. Sidney R. Cohen
5. Semen V. Nesterov
6. Atan Gross

Reviewed by Review Commons

Functionally-Coupled Ion Channels Begin Co-assembling at the Start of Their Synthesis

1. Roya Pournejati
2. Jessica M Huang
3. Michael Ma
4. Claudia M Moreno
5. Oscar Vivas

• Curated by eLife

  eLife Assessment

  This important manuscript provides compelling evidence that BK and CaV1.3 channels can co-localize as ensembles early in the biosynthetic pathway, including in the ER and Golgi. The findings, supported by a range of imaging and proximity assays, offer insights into channel organization in both heterologous and endogenous systems. While the data broadly support the central claims, mechanistic aspects remain unresolved, particularly regarding the determinants of mRNA co-localization, the temporal dynamics of ensemble trafficking, and the physiological implications of pre-assembly for channel function at the plasma membrane.

Reviewed by eLife

Unbend: Correction of local beam-induced sample motion in cryo-EM images using a 3D spline model

1. Lingli Kong
2. Ximena Zottig
3. Johannes Elferich
4. Nikolaus Grigorieff

• Curated by eLife

  eLife Assessment

  This paper describes Unbend - a new method for measuring and correcting motions in cryo-EM images, with a particular emphasis on more challenging in situ samples such as lamella and whole cells. The method, which fits a B-spline model using cross-correlation-based local patch alignment of micrograph frames, represents a valuable tool for the cryo-EM community. The authors elegantly use 2D template matching to provide solid evidence that Unbend outperforms the previously reported method of Unblur by the same authors. The paper would benefit from the inclusion of a similar analysis for established alternative methods, such as MotionCor2.

Reviewed by eLife

Conduction pathway for potassium through the Escherichia coli pump KdpFABC

1. Adel Hussein
2. Xihui Zhang
3. Bjørn P Pedersen
4. David L Stokes

• Curated by eLife

  eLife Assessment

  This manuscript revisits the well-studied KdpFABC potassium transport system from bacteria with a convincing set of new higher resolution structures, a protein expression strategy that permits purification of the active wildtype protein, and insight obtained from mutagenesis and activity assays. The thorough and thoughtful mechanistic analyses make this a valuable contribution to the membrane transport field.

Reviewed by eLife