eLife (Oct 2015)
An internal promoter underlies the difference in disease severity between N- and C-terminal truncation mutations of Titin in zebrafish
- Jun Zou,
- Diana Tran,
- Mai Baalbaki,
- Ling Fung Tang,
- Annie Poon,
- Angelo Pelonero,
- Erron W Titus,
- Christiana Yuan,
- Chenxu Shi,
- Shruthi Patchava,
- Elizabeth Halper,
- Jasmine Garg,
- Irina Movsesyan,
- Chaoying Yin,
- Roland Wu,
- Lisa D Wilsbacher,
- Jiandong Liu,
- Ronald L Hager,
- Shaun R Coughlin,
- Martin Jinek,
- Clive R Pullinger,
- John P Kane,
- Daniel O Hart,
- Pui-Yan Kwok,
- Rahul C Deo
Affiliations
- Jun Zou
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Diana Tran
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Mai Baalbaki
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Ling Fung Tang
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Annie Poon
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Angelo Pelonero
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Erron W Titus
- ORCiD
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Christiana Yuan
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Chenxu Shi
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Shruthi Patchava
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Elizabeth Halper
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Jasmine Garg
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Irina Movsesyan
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States
- Chaoying Yin
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States; McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Roland Wu
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Medicine, University of California, San Francisco, San Francisco, United States
- Lisa D Wilsbacher
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Medicine, University of California, San Francisco, San Francisco, United States
- Jiandong Liu
- Department of Pathology and Laboratory Medicine, University of North Carolina at Chapel Hill, Chapel Hill, United States; McAllister Heart Institute, University of North Carolina at Chapel Hill, Chapel Hill, United States
- Ronald L Hager
- ORCiD
- Department of Exercise Sciences, Brigham Young University, Provo, United States
- Shaun R Coughlin
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Medicine, University of California, San Francisco, San Francisco, United States
- Martin Jinek
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
- Clive R Pullinger
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Physiological Nursing, University of California, San Francisco, San Francisco, United States
- John P Kane
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
- Daniel O Hart
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, United States
- Pui-Yan Kwok
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Dermatology, University of California, San Francisco, San Francisco, United States; Institute for Human Genetics, University of California, San Francisco, United States
- Rahul C Deo
- Cardiovascular Research Institute, University of California, San Francisco, San Francisco, United States; Department of Medicine, University of California, San Francisco, San Francisco, United States; Institute for Human Genetics, University of California, San Francisco, United States; California Institute for Quantitative Biosciences, San Francisco, United States
- DOI
- https://doi.org/10.7554/eLife.09406
- Journal volume & issue
-
Vol. 4
Abstract
Truncating mutations in the giant sarcomeric protein Titin result in dilated cardiomyopathy and skeletal myopathy. The most severely affected dilated cardiomyopathy patients harbor Titin truncations in the C-terminal two-thirds of the protein, suggesting that mutation position might influence disease mechanism. Using CRISPR/Cas9 technology, we generated six zebrafish lines with Titin truncations in the N-terminal and C-terminal regions. Although all exons were constitutive, C-terminal mutations caused severe myopathy whereas N-terminal mutations demonstrated mild phenotypes. Surprisingly, neither mutation type acted as a dominant negative. Instead, we found a conserved internal promoter at the precise position where divergence in disease severity occurs, with the resulting protein product partially rescuing N-terminal truncations. In addition to its clinical implications, our work may shed light on a long-standing mystery regarding the architecture of the sarcomere.
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