The intermediate filament protein GFAP regulates mitochondrial fission in astrocytes

D Ding Xiong Y Ye Sing Tan (Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School) F Fang Yuan Y Yinglu Li (State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University) K Kay En Low (Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore) I Isabelle Bonne (Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore) S Sakthikumar Mathivanan (Center for Neurologic Diseases, Sanford Burnham Prebys Medical Discovery Institute) P Phil Jun Kang (Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School) Z Zijun Sun (Waisman Center, University of Wisconsin-Madison) X Xueyan Li (Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, China) E Emily Abella (Waisman Center, University of Wisconsin-Madison) A Albee Messing (Waisman Center, University of Wisconsin-Madison) L Linghai Kong (Waisman Center, University of Wisconsin-Madison) S Su-Chun Zhang (Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School)

Abstract

Mitochondrial plasticity, coordinated by fission and fusion, is crucial to ensure cellular functions. Mitochondrial fission is mediated by the GTPase Drp1 at the constriction site, which is proposed to be driven by the actin–myosin contractile force. However, the mechanism that propels constriction remains unclear, and the potential involvement of additional mechanisms in this process remains an open question. Here, using structured illumination microscopy, electron microscopy, and correlative light electron microscopy (CLEM), we show that the type III intermediate filament glial fibrillary acidic protein (GFAP) participates in mitochondria constriction and fission by interacting with Drp1. Remarkably, loss of GFAP results in hyperfused mitochondria under physiological and even Ca 2+ -induced mitochondrial fission conditions. Additionally, mutations in GFAP, the cause of Alexander disease, result in more Drp1 localized to GFAP and lead to significantly increased mitochondrial fissions. Taken together, these findings propose a role of type III intermediate filaments in mitochondrial division.

Article Details

Volume / Issue Vol. 122, Issue 48
Published December 02, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (14)

D

Ding Xiong

Y

Ye Sing Tan

Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School

F

Fang Yuan

Y

Yinglu Li

State Key Laboratory of Oral Diseases, National Clinical Research Center for Oral Diseases, West China Hospital of Stomatology, Sichuan University

K

Kay En Low

Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore

I

Isabelle Bonne

Electron Microscopy Unit, Microscopy Cluster, Yong Loo Lin School of Medicine, National University of Singapore

S

Sakthikumar Mathivanan

Center for Neurologic Diseases, Sanford Burnham Prebys Medical Discovery Institute

P

Phil Jun Kang

Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School

Z

Zijun Sun

Waisman Center, University of Wisconsin-Madison

X

Xueyan Li

Key Laboratory of Bio-Inspired Smart Interfacial Science and Technology of Ministry of Education, School of Chemistry, Beihang University, Beijing 100191, China

E

Emily Abella

Waisman Center, University of Wisconsin-Madison

A

Albee Messing

Waisman Center, University of Wisconsin-Madison

L

Linghai Kong

Waisman Center, University of Wisconsin-Madison

S

Su-Chun Zhang

Program in Neuroscience and Behavioural Disorders, Duke-NUS Medical School