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In vivo cell biological screening identifies an endocytic capture mechanism for T-tubule formation.

ABSTRACT: The skeletal muscle T-tubule is a specialized membrane domain essential for coordinated muscle contraction. However, in the absence of genetically tractable systems the mechanisms involved in T-tubule formation are unknown. Here, we use the optically transparent and genetically tractable zebrafish system to probe T-tubule development in vivo. By combining live imaging of transgenic markers with three-dimensional electron microscopy, we derive a four-dimensional quantitative model for T-tubule formation. To elucidate the mechanisms involved in T-tubule formation in vivo, we develop a quantitative screen for proteins that associate with and modulate early T-tubule formation, including an overexpression screen of the entire zebrafish Rab protein family. We propose an endocytic capture model involving firstly, formation of dynamic endocytic tubules at transient nucleation sites on the sarcolemma, secondly, stabilization by myofibrils/sarcoplasmic reticulum and finally, delivery of membrane from the recycling endosome and Golgi complex.

SUBMITTER: Hall TE

PROVIDER: S-EPMC7381618 | biostudies-literature | 2020 Jul

REPOSITORIES: biostudies-literature

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In vivo cell biological screening identifies an endocytic capture mechanism for T-tubule formation.

Hall Thomas E TE Martel Nick N Ariotti Nicholas N Xiong Zherui Z Lo Harriet P HP Ferguson Charles C Rae James J Lim Ye-Wheen YW Parton Robert G RG

Nature communications 20200724 1

The skeletal muscle T-tubule is a specialized membrane domain essential for coordinated muscle contraction. However, in the absence of genetically tractable systems the mechanisms involved in T-tubule formation are unknown. Here, we use the optically transparent and genetically tractable zebrafish system to probe T-tubule development in vivo. By combining live imaging of transgenic markers with three-dimensional electron microscopy, we derive a four-dimensional quantitative model for T-tubule fo ...[more]

PMID: 32709891

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In vivo cell biological screening identifies an endocytic capture mechanism for T-tubule formation.

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In vivo cell biological screening identifies an endocytic capture mechanism for T-tubule formation.

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