Cardiac muscle cell contractions require calcium intake into the cell through L-type calcium channels (Cav1.2) located on tubular membrane invaginations called T-tubules. BIN1, a member of the BAR domain superfamily, can generate membrane invaginations, and was recently reported to tether microtubules to the membrane scaffolding of cardiac T-tubules. These microtubules are used for transport of the Cav1.2 calcium channels to T-tubules. Images above are of a HeLa cell expressing α-tubulin:GFP (black) and BIN1:mCherry (red), showing microtubules tethered to BIN1. Panel on the right shows the travel path of three microtubules (green).
Reference: Ting-Ting Hong, James W. Smyth, Danchen Gao, Kevin Y. Chu, Jacob M. Vogan, Tina S. Fong, Brian C. Jensen, Henry M. Colecraft, Robin M. Shaw. BIN1 Localizes the L-Type Calcium Channel to Cardiac T-Tubules. PLoS Biology 2010, 8(2): e1000312. Article can be found here.
Great synopsis of this work can be found here.