Title: T-Tubule - an overview | ScienceDirect Topics
Headings: T-Tubule
T-Tubule
Ion Channel Trafficking
T-Tubules
Skeletal Muscle
T-tubules Are Surface Invaginations; the SR Is an Internal Membrane System
Structure and Function of Calcium Release Channels
2 T Tubules and CRUs Revert to More Primitive Forms Under Pathological Conditions
Muscles
Coupling Action Potentials to Contraction
The Cellular Basis of Cardiac Contractility
The SR Releases Stored Ca 2+ to Activate Contraction
Disorders of Muscle Excitability
Calcium couples muscle membrane excitation to filament contraction
Muscle physiology
Excitation–contraction coupling
EXERCISE | Muscle
Voltage-dependent Sarcoplasmic Reticulum Ca 2+ Release

Content: T-Tubule - an overview | ScienceDirect Topics
T-Tubule
T tubules extend from the free surface throughout the cells in a generally transverse direction, coursing around the myofibrils at the levels of the Z bands. From: Haschek and Rousseaux's Handbook of Toxicologic Pathology (Third Edition), 2013
Download as PDF
About this page
Ion Channel Trafficking
T.T. Hong, R.M. Shaw, in Ion Channels in Health and Disease, 2016
T-Tubules
T-tubule membrane is associated with a unique set of ion channels supported by membrane structural subdomains.23 Immunocytochemistry and patch clamp data indicate that 80% of the sarcolemma LTCCs are concentrated at T-tubules. Localization of LTCCs to T-tubules is critical in bringing LTCCs to the vicinity of calcium sense and release channel RyR at SR membrane. Approximation of LTCCs and RyRs form a functional microdomain, the cardiac dyads, which are the individual calcium-releasing units in cardiomyocytes. As discussed earlier, Targeted Delivery also applies to Cav1.2 channel localization to T-tubule surface, which requires a membrane scaffolding protein BIN1. 26 Interestingly, BIN1 also forms minifolds within T-tubules, affecting extracellular ion diffusion thereby controlling the driving force of Cav1.2 channel activity. 6 BIN1-folded subdomains within T-tubules may also limit LTCC lateral diffusion once the channels are inserted into T-tubule membrane, to maintain functional LTCC-RyR dyads. Therefore, BIN1-like membrane scaffold proteins may help localize particular pools of ion channel proteins to membrane subdomains for compartmentalized regulation of ion channel activity and function. Similarly, ankyrin B can play a role similar to BIN1 in clustering NCX/NKA/InsP3 complex to microdomains distinct from the dyads.