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Myofibril diameter is set by a finely tuned mechanism of protein oligomerization in Drosophila

Authors :
Nicanor González-Morales
Yu Shu Xiao
Matthew Aaron Schilling
Océane Marescal
Kuo An Liao
Frieder Schöck
Source :
eLife, Vol 8 (2019)
Publication Year :
2019
Publisher :
eLife Sciences Publications Ltd, 2019.

Abstract

Myofibrils are huge cytoskeletal assemblies embedded in the cytosol of muscle cells. They consist of arrays of sarcomeres, the smallest contractile unit of muscles. Within a muscle type, myofibril diameter is highly invariant and contributes to its physiological properties, yet little is known about the underlying mechanisms setting myofibril diameter. Here we show that the PDZ and LIM domain protein Zasp, a structural component of Z-discs, mediates Z-disc and thereby myofibril growth through protein oligomerization. Oligomerization is induced by an interaction of its ZM domain with LIM domains. Oligomerization is terminated upon upregulation of shorter Zasp isoforms which lack LIM domains at later developmental stages. The balance between these two isoforms, which we call growing and blocking isoforms sets the stereotyped diameter of myofibrils. If blocking isoforms dominate, myofibrils become smaller. If growing isoforms dominate, myofibrils and Z-discs enlarge, eventually resulting in large pathological aggregates that disrupt muscle function.

Details

Language :
English
ISSN :
2050084X
Volume :
8
Database :
Directory of Open Access Journals
Journal :
eLife
Publication Type :
Academic Journal
Accession number :
edsdoj.f9789045067d4b7998edb7eacd398ff8
Document Type :
article
Full Text :
https://doi.org/10.7554/eLife.50496