title: The LGI1/epitempin gene encodes two protein isoforms differentially expressed in human brain.
abstract: The leucine-rich, glioma inactivated 1 (LGI1)/Epitempin gene has been linked to two phenotypes as different as gliomagenesis and autosomal dominant lateral temporal epilepsy. Its function and the biochemical features of the encoded protein are unknown. We characterized the LGI1/Epitempin protein product by western blot analysis of mouse and human brain tissues. Two proteins of about 60 and 65 kDa were detected by an anti-LGI1 antibody within the expected molecular mass range. The two proteins appeared to reside in different subcellular compartments, as they were fractionated by differential centrifugation. The specificity of both polypeptides was validated by cell transfection assay and mass spectrometry analysis. Immunoblot analysis of protein distribution in various zones of the human brain revealed variable amounts of both proteins. Notably, these proteins were more abundant in the temporal neocortex than in the hippocampus, the difference in abundance of the 65-kDa product being particularly pronounced. These results suggest that the two protein isoforms encoded by LGI1/Epitempin are differentially expressed in the human brain, and that higher expression levels of these proteins in the lateral temporal cortex may underlie the susceptibility of this brain region to the epileptogenic effects of LGI1/Epitempin mutations.
authors.affiliation: CNR-Istituto di Neuroscienze, Sezione di Padova, Dipartimento di Scienze Biomediche Sperimentali, Università di Padova, Padua, Italy.
authors.forename: Sandra
authors.initials: S
authors.lastname: Furlan
authors.forename: Federico
authors.initials: F
authors.lastname: Roncaroli
authors.forename: Francesca
authors.initials: F
authors.lastname: Forner
authors.forename: Libero
authors.initials: L
authors.lastname: Vitiello
authors.forename: Elisa
authors.initials: E
authors.lastname: Calabria
authors.forename: Salomé
authors.initials: S
authors.lastname: Piquer-Sirerol
authors.forename: Giorgio
authors.initials: G
authors.lastname: Valle
authors.forename: Jordi
authors.initials: J
authors.lastname: Perez-Tur
authors.forename: Roberto
authors.initials: R
authors.lastname: Michelucci
authors.forename: Carlo
authors.initials: C
authors.lastname: Nobile
mesh_terms: D000369:Aged, 80 and over; D000595:Amino Acid Sequence; D000818:Animals; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D020022:Genetic Predisposition to Disease; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008969:Molecular Sequence Data; D009154:Mutation; D020033:Protein Isoforms / Q000096:biosynthesis / Q000235:genetics; D011506:Proteins / Q000235:genetics* / Q000378:metabolism*
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; C116499:LGI1 protein, human; C492120:Lgi1 protein, mouse; D020033:Protein Isoforms; D011506:Proteins