The critical role of membralin in postnatal motor neuron survival and disease
Abstract
Hitherto, membralin has been a protein of unknown function. Here, we show that membralin mutant mice manifest a severe and early-onset motor neuron disease in an autosomal recessive manner, dying by postnatal day 5-6. Selective death of lower motor neurons, including those innervating the limbs, intercostal muscles, and diaphragm, are predominantly responsible for this fatal phenotype. Neural expression of a membralin transgene completely rescues membralin mutant mice. Mechanistically, we show that membralin interacts with Erlin2, an endoplasmic reticulum (ER) membrane protein that is located in lipid rafts and known to be important in ER-associated protein degradation (ERAD). Accordingly, the degradation rate of ERAD substrates is attenuated in cells lacking membralin. Membralin mutations or deficiency in mouse models induce ER stress, rendering neurons more vulnerable to cell death. Our study reveals a critical role of membralin in motor neuron survival and suggests a novel mechanism for early-onset motor neuron disease.
Article and author information
Author details
Ethics
Animal experimentation: All described procedures for animal were approved by the Institutional Animal Care and Use Committee of Sanford-Burnham Medical Research Institute and conducted in compliance with the Guide for the Care and Use of Laboratory Animals (Animal Use Form #14-060). Both sexes of mice were used for experiments and maintained in an institute facility accredited by the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC).
Copyright
© 2015, Yang et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
Metrics
-
- 1,732
- views
-
- 365
- downloads
-
- 12
- citations
Views, downloads and citations are aggregated across all versions of this paper published by eLife.
Download links
Downloads (link to download the article as PDF)
Open citations (links to open the citations from this article in various online reference manager services)
Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)
Further reading
-
- Neuroscience
Our propensity to materiality, which consists in using, making, creating, and passing on technologies, has enabled us to shape the physical world according to our ends. To explain this proclivity, scientists have calibrated their lens to either low-level skills such as motor cognition or high-level skills such as language or social cognition. Yet, little has been said about the intermediate-level cognitive processes that are directly involved in mastering this materiality, that is, technical cognition. We aim to focus on this intermediate level for providing new insights into the neurocognitive bases of human materiality. Here, we show that a technical-reasoning process might be specifically at work in physical problem-solving situations. We found via two distinct neuroimaging studies that the area PF (parietal F) within the left parietal lobe is central for this reasoning process in both tool-use and non-tool-use physical problem-solving and can work along with social-cognitive skills to resolve day-to-day interactions that combine social and physical constraints. Our results demonstrate the existence of a specific cognitive module in the human brain dedicated to materiality, which might be the supporting pillar allowing the accumulation of technical knowledge over generations. Intensifying research on technical cognition could nurture a comprehensive framework that has been missing in fields interested in how early and modern humans have been interacting with the physical world through technology, and how this interaction has shaped our history and culture.
-
- Neuroscience
Moment-to-moment neural variability has been shown to scale positively with the complexity of stimulus input. However, the mechanisms underlying the ability to align variability to input complexity are unknown. Using a combination of behavioral methods, computational modeling, fMRI, MR spectroscopy, and pharmacological intervention, we investigated the role of aging and GABA in neural variability during visual processing. We replicated previous findings that participants expressed higher variability when viewing more complex visual stimuli. Additionally, we found that such variability modulation was associated with higher baseline visual GABA levels and was reduced in older adults. When pharmacologically increasing GABA activity, we found that participants with lower baseline GABA levels showed a drug-related increase in variability modulation while participants with higher baseline GABA showed no change or even a reduction, consistent with an inverted-U account. Finally, higher baseline GABA and variability modulation were jointly associated with better visual-discrimination performance. These results suggest that GABA plays an important role in how humans utilize neural variability to adapt to the complexity of the visual world.