Cell Biology

UGGT1-mediated reglucosylation of N-glycan competes with ER-associated degradation of unstable and misfolded glycoproteins

1. Satoshi Ninagawa
2. Masaki Matsuo
3. Deng Ying
4. Shuichiro Oshita
5. Shinya Aso
6. Kazutoshi Matsushita
7. Mai Taniguchi
8. Akane Fueki
9. Moe Yamashiro
10. Kaoru Sugasawa
11. Shunsuke Saito
12. Koshi Imami
13. Yasuhiko Kizuka
14. Tetsushi Sakuma
15. Takashi Yamamoto
16. Hirokazu Yagi
17. Koichi Kato
18. Kazutoshi Mori

• Curated by eLife

  eLife Assessment

  This important manuscript demonstrates that UGGT1 is involved in preventing the premature degradation of endoplasmic reticulum (ER) glycoproteins through the re-glucosylation of their N-linked glycans following release from the calnexin/calreticulin lectins. The authors include a wealth of convincing data in support of their findings, although extending these findings to other types of substrates, such as secreted proteins, could further demonstrate the global importance of this mechanism for protein trafficking through the secretory pathway. This work will be of interest to scientists interested in ER protein quality control, proteostasis, and protein trafficking.

Reviewed by eLife

MuSK-BMP signaling in adult muscle stem cells maintains quiescence and regulates myofiber size

1. Laura A Madigan
2. Diego Jaime
3. Isabella Chen
4. Justin R Fallon

• Curated by eLife

  eLife Assessment

  This valuable study provides solid support for the participation of the BMP-binding domain of MuSK, a tyrosine kinase mostly known for its role at the neuromuscular junction, in the maintenance and activation of muscle stem cells (SCs). These mononucleated cells, located between the muscle fiber basal lamina and its plasma membrane, are normally quiescent, but following muscle damage, become activated, proliferate, and mediate muscle regeneration. These cells are known to respond to a variety of signaling pathways, but this study makes the case for BMP acting via binding to MuSK in maintaining the quiescent state.

Reviewed by eLife

Quantitative phase imaging with temporal kinetics predicts hematopoietic stem cell diversity

1. Takao Yogo
2. Yuichiro Iwamoto
3. Hans Jiro Becker
4. Takaharu Kimura
5. Reiko Ishida
6. Ayano Sugiyama-Finnis
7. Tomomasa Yokomizo
8. Toshio Suda
9. Sadao Ota
10. Satoshi Yamazaki

Reviewed by Arcadia Science

The exocyst complex controls multiple events in the pathway of regulated exocytosis

1. Sofía Suárez Freire
2. Sebastián Perez-Pandolfo
3. Sabrina Micaela Fresco
4. Julián Valinoti
5. Eleonora Sorianello
6. Pablo Wappner
7. Mariana Melani

• Curated by eLife

  eLife Assessment

  This study makes an important contribution by characterizing the role of the exocyst in secretory granule exocytosis in the Drosophila larval salivary gland. The results are solid and lead to the novel interpretation that the exocyst participates not only in exocytosis, but also in earlier steps of secretory granule biogenesis and maturation. However, the authors are urged to provide additional proof that the exocyst subunit knockdowns were effective and to acknowledge the possibility that inactivation of an essential exocytosis component could indirectly affect other parts of the secretory pathway.

Reviewed by eLife

Multi-color fluorescence live-cell imaging in Dictyostelium discoideum

1. Hidenori Hashimura
2. Satoshi Kuwana
3. Hibiki Nakagwa
4. Kenichi Abe
5. Tomoko Adachi
6. Toyoko Sugita
7. Shoko Fujishiro
8. Gen Honda
9. Satoshi Sawai

Reviewed by Arcadia Science

Genome concentration limits cell growth and modulates proteome composition in Escherichia coli

1. Jarno Mäkelä
2. Alexandros Papagiannakis
3. Wei-Hsiang Lin
4. Michael Charles Lanz
5. Skye Glenn
6. Matthew Swaffer
7. Georgi K Marinov
8. Jan M Skotheim
9. Christine Jacobs-Wagner

• Curated by eLife

  eLife Assessment

  This fundamental work by Mäkelä et al. presents compelling experimental evidence supported by a theoretical model that the amount of chromosomal DNA can become limiting for the total rate of mRNA transcription and consequently protein production in the model bacterium Escherichia coli. The work is based on a mutant that allows inhibition of DNA replication while following growth at the single-cell level due to cell filamentation. The work significantly advances our understanding of growth and of the central dogma, and will be of considerable interest within both systems biology and microbial physiology.

Reviewed by eLife

Single-nucleus transcriptomics reveal the differentiation trajectories of periosteal skeletal/stem progenitor cells in bone regeneration

1. Simon Perrin
2. Maria Ethel
3. Vincent Bretegnier
4. Cassandre Goachet
5. Cécile-Aurore Wotawa
6. Marine Luka
7. Fanny Coulpier
8. Cécile Masson
9. Mickael Ménager
10. Céline Colnot

• Curated by eLife

  eLife Assessment

  This fundamental study generated a single cell atlas of mouse periosteal cells under both steady-state and fracture healing conditions to address the knowledge gap regarding cellular composition of the periosteum and their responses to injury. Based on convincing transcriptome analyses and experimental validation, the authors identified the injury induced fibrogenic cell (IIFC) as a characteristic cell type appearing in the bone regeneration process and proposed that the IIFC is a progenitor undergoing osteochondrogenic differentiation. This study will provide a significant publicly accessible dataset to reexamine the expression of the reported periosteal stem and progenitor cell markers.

Reviewed by eLife

Long range mutual activation establishes Rho and Rac polarity during cell migration

1. Henry De Belly
2. Andreu Fernandez Gallen
3. Evelyn Strickland
4. Dorothy C. Estrada
5. Patrick J. Zager
6. Tamas L. Nagy
7. Janis K Burkhardt
8. Hervé Turlier
9. Orion D. Weiner

Reviewed by preLights

Intracellular diffusion in the cytoplasm increases with cell size in fission yeast

1. Catherine Tan
2. Michael C. Lanz
3. Matthew Swaffer
4. Jan Skotheim
5. Fred Chang

Reviewed by preLights

PKA regulation of neuronal function requires the dissociation of catalytic subunits from regulatory subunits

1. Weihong Xiong
2. Maozhen Qin
3. Haining Zhong

• Curated by eLife

  eLife Assessment

  This important paper demonstrates that different PKA subtypes exhibit distinct subcellular localization at rest in CA1 neurons. The authors provide compelling evidence that when all tested PKA subtypes are activated by norepinephrine, catalytic subunits translocate to dendritic spines but regulatory subunits remain unmoved. Furthermore, PKA-dependent regulation of synaptic plasticity and transmission can be supported only by wildtype, dissociable PKA, but not by inseparable PKA.

Reviewed by eLife