LABORATORY OF INTRACELLULAR ION CHANNELS: How do we know what type of membranes we are studying?

Friday, July 27, 2007

How do we know what type of membranes we are studying?

Intracellular membranes and their channels must be carefully extracted from the interior of the cell. To obtain heavy sarcoplasmic reticulum membranes enrichedd in RyR2, mice hearts are homogenized and fractionated by differential centrifugation under a sucrose gradient. Marcia Cortés-Gutiérrez has developed simple methods to quickly separate SR membranes with functionaly intact RyR2 channels. Biochemical and electrophysiological analysis reveal that a microsomal fraction can be obtained which contains RyR2 and its anxiliary proteins.

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Publications

Chen R, Valencia I, Zhong F, McColl KS, Roderick HL, Bootman MD, Berridge MJ, Conway SJ, Holmes AB, Mignery GA, Velez P, Distelhorst CW. Bcl-2 functionally interacts with inositol 1,4,5-trisphosphate receptors to regulate calcium release from the ER in response to inositol 1,4,5-trisphosphate. J Cell Biol. 2004 Jul 19;166(2):193-203.
Zoghbi ME, Copello JA, Villalba-Galea CA, Velez P, Diaz Sylvester PL, Bolanos P, Marcano A, Fill M, Escobar AL. Differential Ca2+ and Sr2+ regulation of intracellular divalent cations release in ventricular myocytes. Cell Calcium. 2004 Aug;36(2):119-34.
VVelez P, Sierralta J, Alcayaga C, Fonseca M, Loyola H, Johns DC, Tomaselli GF, Marban E, Suarez-Isla BA. A functional assay for paralytic shellfish toxins that uses recombinant sodium channels. Toxicon. 2001 Jul;39(7):929-35.
Li RA, Ennis IL, Velez P, Tomaselli GF, Marban E. Novel structural determinants of mu-conotoxin (GIIIB) block in rat skeletal muscle (µ1) Na+ channels. J Biol Chem. 2000 Sep 8;275(36):27551-8.
Li RA, Velez P, Chiamvimonvat N, Tomaselli GF, Marban E. Charged residues between the selectivity filter and S6 segments contribute to the permeation phenotype of the sodium channel. J Gen Physiol. 2000 Jan;115(1):81-92.
Escobar AL, Velez P, Kim AM, Cifuentes F, Fill M, Vergara JL. Kinetic properties of DM-nitrophen and calcium indicators: rapid transient response to flash photolysis. Pflugers Arch. 1997 Sep;434(5):615-31.
Satoh H, Katoh H, Velez P, Fill M, Bers DM. Bay K 8644 increases resting Ca2+ spark frequency in ferret ventricular myocytes independent of Ca influx: contrast with caffeine and ryanodine effects. Circ Res. 1998 Dec 14-28;83(12):1192-204.
Velez P, Gyorke S, Escobar AL, Vergara J, Fill M. Adaptation of single cardiac ryanodine receptor channels. Biophys J. 1997 Feb;72(2 Pt 1):691-7.
Uehara A, Fill M, Velez P, Yasukochi M, Imanaga I. Rectification of rabbit cardiac ryanodine receptor current by endogenous polyamines. Biophys J. 1996 Aug;71(2):769-77.
Armisen R, Sierralta J, Velez P, Naranjo D, Suarez-Isla BA. Modal gating in neuronal and skeletal muscle ryanodine-sensitive Ca2+ release channels. Am J Physiol. 1996 Jul;271(1 Pt 1):C144-53.
Tu Q, Velez P, Brodwick M, Fill M. Streaming potentials reveal a short ryanodine-sensitive selectivity filter in cardiac Ca2+ release channel. Biophys J. 1994 Dec;67(6):2280-5.
Fruen BR, Mickelson JR, Shomer NH, Velez P, Louis CF. Cyclic ADP-ribose does not affect cardiac or skeletal muscle ryanodine receptors. FEBS Lett. 1994 Sep 26;352(2):123-6
Gyorke S, Velez P, Suarez-Isla B, Fill M. Activation of single cardiac and skeletal ryanodine receptor channels by flash photolysis of caged Ca2+. Biophys J. 1994 Jun;66(6):1879-86.
Tu Q, Velez P, Cortes-Gutierrez M, Fill M. Surface charge potentiates conduction through the cardiac ryanodine receptor channel. J Gen Physiol. 1994 May;103(5):853-67.