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α 1 and α 2 Ca 2+ channel subunit expression in human neuronal and small cell carcinoma cells
Author(s) -
Morton Mary E.,
Cassidy Tara N.,
Froehner Stanley C.,
Gilmour Brian P.,
Laurens Robin L.
Publication year - 1994
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.8.11.8070639
Subject(s) - protein subunit , channel (broadcasting) , chemistry , cell , microbiology and biotechnology , biology , gene , biochemistry , computer science , computer network
Monoclonal antibodies that recognize skeletal muscle dihydropyridine‐sensitive calcium channel subunits were used to identify similar proteins in neuronal and small cell carcinoma cell lines. α 1 ‐related proteins were detected by FACS analysis on the surface of human neuroblastoma (IMR 32) and small cell carcinoma (DMS 273 and DMS 114) cell lines. α 1 ‐like polypeptides from these cells were isolated and partially characterized. The polypeptides exhibit an M r similar to that of the L‐type channel α 1 subunit and are recognized by two distinct anti‐ α1 mAbs. The data provide biochemical evidence for structural similarities between the α 1 sub‐unit of small cell carcinoma and neuronal cell lines. Similarly, an α 2 ‐like protein was characterized from these cells. Because α 2 is a subunit shared by many subtypes of calcium channels, these data suggest that subunits other than the pore‐forming α 1 subunit may play an important role in the etiology of Lambert‐Eaton syndrome. We demonstrate directly that small cell carcinoma and a cell line derived from peripheral neurons share L‐type calcium channel‐related proteins and a protein common to many voltage‐gated calcium channel subtypes. These data support a model that proposes that cross‐reactivity of anti‐tumor cell antibodies with presynaptic elements, possibly calcium channels, plays a role in the development of Lambert‐Eaton syndrome.— Morton, M. E., Cassidy, T. N., Froehner, S. C., Gilmour, B. P., Laurens, R. L. α 1 and α 2 Ca 2+ channel subunit expression in human neuronal and small cell carcinoma cells. FASEB J. 8: 884‐888; 1994.