Abstract
The TREX-2 complex integrates several stages of gene expression, such as transcriptional activation and mRNA export. In D. melanogaster TREX-2 consists of four main proteins: Xmas-2, ENY2, PCID2, and Sem1p. Xmas-2 protein is the core subunit of the complex with which other TREX-2 subunits interact. Xmas-2 homologues have been found in all higher eukaryotes. Previously, it was shown that the human Xmas-2 homologue, GANP protein can undergo cleavage into two parts, probably during apoptotic cell death. We showed that the Xmas-2 protein of D. melanogaster also can split into two fragments. The resulting fragments of the protein correspond to the two large domains of Xmas-2. Protein splitting is observed both in vivo and in vitro. However, Xmas-2 cleavage in D. melanogaster is observed under normal conditions and is probably a part of the mechanism of transcription and mRNA export regulation in D. melanogaster.