Evidence for a 95 kDa Short Form of the α_1A Subunit Associated with the ω-Conotoxin MVIIC Receptor of the P/Q-type Ca²⁺ Channels

R.F. is supported by a Human Frontier Science Program postdoctoral fellowship. K.P.C. is an Investigator of the Howard Hughes Medical Institute (HHMI). The protein sequencing was performed by Dr. C. A. Slaughter and C. Moomaw at the HHMI Biopolymers Facility (University of Texas Southwestern Medical Center, Dallas, TX) and by R. F. Cook and N. Thorngren at the Biopolymers Laboratory, Center for Cancer Research (MIT, Cambridge, MA). Monoclonal antibody CC 18 was raised in collaboration with Dr. V. A. Lennon (Mayo Clinic, Rochester, MN). We thank J. C. Miller for his expert technical assistance. We are also grateful to C. Leveille, D. Venzke, and Drs. G. Biddlecome, K. Bielefeldt, and C. A. Gurnett for critically reading this manuscript.

Correspondence should be addressed to Dr. Kevin P. Campbell, Howard Hughes Medical Institute, University of Iowa College of Medicine, 400 Eckstein Medical Research Building, Iowa City, IA 52242.

Dr. Scott’s present address: Department of Neurological and Urological Disease Research (D47C), Abbott Laboratories, Abbott Park, IL 60064.