EFCAB10 anchors AK8 to the radial spoke for proper ciliary motility

T Ting Song (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) Q Qingchao Li (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) Q Qian Lyu (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) J Junkui Zhao (State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University) X Xirui Zi (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) S Shuxiang Ma (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) J Jiajun Luo (Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences) S Shushen Li (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) S Shanshan Nai (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University) H Hongbin Liu (Cheeloo College of Medicine, Shandong University) X Xueliang Zhu (Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences) T Te Li (State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University) J Jun Zhou H Huijie Zhao (Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University)

Abstract

Radial spokes in motile cilia and flagella regulate rhythmic ciliary motility, which is essential for rapid cell movement and extracellular fluid flow. In humans, defective radial spokes can cause a genetic disorder known as primary ciliary dyskinesia (PCD), resulting in respiratory defects and infertility. Despite their critical role in ciliary motility, the molecular composition and related physiological functions remain to be elucidated. Here, we identify EF-hand calcium-binding domain protein 10 (EFCAB10) and adenylate kinase (AK8) as radial spoke proteins and describe their roles in mouse motile cilia. Using Efcab10 −/− and Ak8 −/− mice, we show that loss of either protein can affect ciliary motility and lead to PCD-related phenotypes in mice. Interestingly, ciliary AK8 is completely absent in Efcab10 −/− cilia, but the loss of AK8 has no effect on ciliary EFCAB10. Further biochemical analyses reveal that EFCAB10 interacts with AK8 and RSPH3B, which fastens AK8 to the radial spoke. Overall, our findings demonstrate the essential role of EFCAB10 as a radial spoke protein in maintaining the integrity of the radial spoke and provide valuable insights into the molecular basis of related ciliopathies.

Article Details

Volume / Issue Vol. 122, Issue 41
Published October 14, 2025
ISSN 0027-8424
Publisher National Academy of Sciences

Authors (14)

T

Ting Song

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

Q

Qingchao Li

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

Q

Qian Lyu

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

J

Junkui Zhao

State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University

X

Xirui Zi

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

S

Shuxiang Ma

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

J

Jiajun Luo

Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences

S

Shushen Li

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

S

Shanshan Nai

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University

H

Hongbin Liu

Cheeloo College of Medicine, Shandong University

X

Xueliang Zhu

Key Laboratory of Multi-Cell Systems, Shanghai Institute of Biochemistry and Cell Biology, Center for Excellence in Molecular Cell Science, University of Chinese Academy of Sciences, Chinese Academy of Sciences

T

Te Li

State Key Laboratory of Medicinal Chemical Biology, Haihe Laboratory of Cell Ecosystem, College of Life Sciences, Nankai University

J

Jun Zhou

H

Huijie Zhao

Center for Cell Structure and Function, Shandong Provincial Key Laboratory of Animal Resistance Biology, College of Life Sciences, Shandong Normal University