Channelpedia

Cloning and characterization of a Lambert-Eaton myasthenic syndrome antigen.


Authors: M R Rosenfeld, E Wong, J Dalmau, G Manley, J B Posner, E Sher, H M Furneaux

Journal, date & volume: Ann. Neurol., 1993 Jan , 33, 113-20

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/8494331

Channelpedia reference in: cacnb2

Abstract
Lambert-Eaton myasthenic syndrome is a paraneoplastic neuromuscular disorder in which an immune response directed against a small-cell lung tumor crossreacts with antigens in the neuromuscular junction. To isolate and characterize the antigens, we screened a human fetal brain expression library with a high-titer serum from a patient with Lambert-Eaton myasthenic syndrome. This screening resulted in the isolation of a complementary DNA clone encoding an antigen we call myasthenic syndrome antigen B (MysB). Approximately 43% (3 of 7) of Lambert-Eaton myasthenic syndrome sera specifically recognized MysB fusion protein, whereas none of 34 control sera did. The predicted amino acid sequence of this clone shows a high degree of homology to the beta subunit of calcium channel complexes. The MysB pre-messenger RNA is alternatively spliced to yield 3 forms of the protein differing in the domain between two highly conserved alpha-helical segments.