Format

Send to

Choose Destination
Free Radic Biol Med. 2018 May 20;120:380-394. doi: 10.1016/j.freeradbiomed.2018.04.007. Epub 2018 Apr 7.

The cysteine residue of glial fibrillary acidic protein is a critical target for lipoxidation and required for efficient network organization.

Author information

1
Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas, C.S.I.C. Ramiro de Maeztu, 9, 28040 Madrid, Spain.
2
Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 9 A, Gothenburg, Sweden.
3
Laboratory of Astrocyte Biology and CNS Regeneration, Center for Brain Repair, Department of Clinical Neuroscience, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Medicinaregatan 9 A, Gothenburg, Sweden; Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia; University of Newcastle, New South Wales, Australia.
4
Department of Structural and Chemical Biology, Centro de Investigaciones Biológicas, C.S.I.C. Ramiro de Maeztu, 9, 28040 Madrid, Spain. Electronic address: dperezsala@cib.csic.es.

Abstract

The type III intermediate filament protein glial fibrillary acidic protein (GFAP) contributes to the homeostasis of astrocytes, where it co-polymerizes with vimentin. Conversely, alterations in GFAP assembly or degradation cause intracellular aggregates linked to astrocyte dysfunction and neurological disease. Moreover, injury and inflammation elicit extensive GFAP organization and expression changes, which underline reactive gliosis. Here we have studied GFAP as a target for modification by electrophilic inflammatory mediators. We show that the GFAP cysteine, C294, is targeted by lipoxidation by cyclopentenone prostaglandins (cyPG) in vitro and in cells. Electrophilic modification of GFAP in cells leads to a striking filament rearrangement, with retraction from the cell periphery and juxtanuclear condensation in thick bundles. Importantly, the C294S mutant is resistant to cyPG addition and filament disruption, thus highlighting the critical role of this residue as a sensor of oxidative damage. However, GFAP C294S shows defective or delayed network formation in GFAP-deficient cells, including SW13/cl.2 cells and GFAP- and vimentin-deficient primary astrocytes. Moreover, GFAP C294S does not effectively integrate with and even disrupts vimentin filaments in the short-term. Interestingly, short-spacer bifunctional cysteine crosslinking produces GFAP-vimentin heterodimers, suggesting that a certain proportion of cysteine residues from both proteins are spatially close. Collectively, these results support that the conserved cysteine residue in type III intermediate filament proteins serves as an electrophilic stress sensor and structural element. Therefore, oxidative modifications of this cysteine could contribute to GFAP disruption or aggregation in pathological situations associated with oxidative or electrophilic stress.

KEYWORDS:

Astrocytes; Cysteine modification; GFAP; Lipoxidation; Neurodegeneration; Oxidative stress; Protein aggregation; Vimentin

[Indexed for MEDLINE]
Free full text

Supplemental Content

Full text links

Icon for Elsevier Science
Loading ...
Support Center