Linear ubiquitination triggers Amph-mediated T-tubule biogenesis.

ABSTRACT: Transverse tubules (T-tubules) are invaginations of the muscle plasma membrane that facilitate rapid transmission of action potentials, ensuring synchronized muscle contraction. Despite their essential role in muscle physiology, the mechanisms underlying T-tubule formation remain elusive. Here, we identify LUBEL/RNF31, a ubiquitin E3 ligase responsible for linear (M1-linked) ubiquitination, as a key regulator of T-tubule biogenesis in Drosophila. Loss of LUBEL leads to Amphiphysin (Amph)-positive membrane sheets instead of tubular networks. The ubiquitin ligase activity of LUBEL and direct interaction with Amph, a BAR domain protein involved in membrane tubulation, are crucial for proper T-tubule morphology. LUBEL and M1-linked ubiquitin chains assemble into puncta on membranes thro

SUBMITTER: Kawaguchi K 

PROVIDER: S-EPMC12778051 | biostudies-literature | 2026 Jan

REPOSITORIES: biostudies-literature