TY - JOUR A1 - Wolfahrt, Sonja A1 - Herman, Sandra A1 - Scholz, Claus-Jürgen A1 - Sauer, Georg A1 - Deissler, Helmut T1 - Identification of alternative transcripts of rat CD9 expressed by tumorigenic neural cell lines and in normal tissues JF - Genetics and Molecular Biology N2 - CD9 is the best-studied member of the tetraspanin family of transmembrane proteins. It is involved in various fundamental cellular processes and its altered expression is a characteristic of malignant cells of different origins. Despite numerous investigations confirming its fundamental role, the heterogeneity of CD9 or other tetraspanin proteins was considered only to be caused by posttranslational modification, rather than alternative splicing. Here we describe the first identification of CD9 transcript variants expressed by cell lines derived from fetal rat brain cells. Variant mRNA-B lacks a potential translation initiation codon in the alternative exon 1 and seems to be characteristic of the tumorigenic BT cell lines. In contrast, variant mRNA-C can be translated from a functional initiation codon located in its extended exon 2, and substantial amounts of this form detected in various tissues suggest a contribution to CD9 functions. From the alternative sequence of variant C, a different membrane topology ( 5 transmembrane domains) and a deviating spectrum of functions can be expected. KW - tetraspanin KW - CD9 KW - antigen KW - cancer KW - noncoding RNAs KW - nervous system KW - poor prognosis KW - tetraspanin protein KW - transcript KW - splice variant KW - membrane topology Y1 - 2013 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-131801 VL - 36 IS - 2 ER -