A Surveillance Function of the HSPB8-BAG3-HSP70 Chaperone complex ensures stress granule integrity and dynamism
Articolo
Data di Pubblicazione:
2016
Citazione:
A Surveillance Function of the HSPB8-BAG3-HSP70 Chaperone complex ensures stress granule integrity and dynamism / M. Ganassi, D. Mateju, I. Bigi, L. Mediani, I. Poser, H.O. Lee, S.J. Seguin, F.F. Morelli, J. Vinet, G. Leo, O. Pansarasa, C. Cereda, A. Poletti, S. Alberti, S. Carra. - In: MOLECULAR CELL. - ISSN 1097-4164. - 63:5(2016), pp. 796-810. [10.1016/j.molcel.2016.07.021]
Abstract:
Stress granules (SGs) are ribonucleoprotein complexes induced by stress. They sequester mRNAs and disassemble when the stress subsides, allowing translation restoration. In amyotrophic lateral sclerosis (ALS), aberrant SGs cannot disassemble and therefore accumulate and are degraded by autophagy. However, the molecular events causing aberrant SG formation and the molecular players regulating this transition are largely unknown. We report that defective ribosomal products (DRiPs) accumulate in SGs and promote a transition into an aberrant state that renders SGs resistant to RNase. We show that only a minor fraction of aberrant SGs is targeted by autophagy, whereas the majority disassembles in a process that requires assistance by the HSPB8-BAG3-HSP70 chaperone complex. We further demonstrate that HSPB8-BAG3-HSP70 ensures the functionality of SGs and restores proteostasis by targeting DRiPs for degradation. We propose a system of chaperone-mediated SG surveillance, or granulostasis, which regulates SG composition and dynamics and thus may play an important role in ALS.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
amyotrophic-lateral-sclerosis; E3 ubiquitin ligase; misfolded proteins; motor neuropathy; phase-transition; autophagy; HSPB8; BAG3; ALS; proteasome
Elenco autori:
M. Ganassi, D. Mateju, I. Bigi, L. Mediani, I. Poser, H.O. Lee, S.J. Seguin, F.F. Morelli, J. Vinet, G. Leo, O. Pansarasa, C. Cereda, A. Poletti, S. Alberti, S. Carra
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