Gene Section Review Atlas Genet Cytogenet Oncol Haematol. 2014; 18(5) 334 Atlas of Genetics and Cytogenetics in Oncology and Haematology INIST-CNRS OPEN ACCESS JOURNAL SIVA1 (SIVA1, Apoptosis-Inducing Factor) João Agostinho Machado-Neto, Fabiola Traina Hematology and Hemotherapy Center-University of Campinas/Hemocentro-Unicamp, Instituto Nacional de Ciencia e Tecnologia do Sangue, Campinas, Sao Paulo, Brazil (JAMN, FT), Hematology/Oncology Division, Department of Internal Medicine, Medical School of Ribeirao Preto, University of Sao Paulo, Ribeirao Preto, Brazil (FT) Published in Atlas Database: October 2013 Online updated version : http://AtlasGeneticsOncology.org/Genes/SIVA1ID42301ch14q32.html DOI: 10.4267/2042/53646 This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 2.0 France Licence. © 2014 Atlas of Genetics and Cytogenetics in Oncology and Haematology Abstract Review on SIVA1, with data on DNA/RNA, on the protein encoded and where the gene is implicated. Identity Other names: CD27BP, SIVA, Siva-1, Siva-2 HGNC (Hugo): SIVA1 Location: 14q32.33 DNA/RNA Description The entire SIVA1 gene is about 15.3 Kb and contains 4 exons (Start: 105219437 bp and End: 105234831; Orientation: plus strand). Two alternatively-spliced transcript variants encoding distinct proteins have been described, SIVA1 transcript variant 1, which is the predominant transcript variant with a cDNA containing 790 bp (codifying the SIVA1 protein), and the SIVA1 transcript variant 2 lacking the exon 2 with a cDNA containing 595 bp (codifying the SIVA2 protein). Protein Description SIVA1 contains a unique amphipathic helical region (SAH) in the N-terminal region, a death domain homology region (DDHR) in the central part of the protein, and a Zinc finger-like structure at its C-terminal region. The SIVA2 isoform lacks the DDHR domain (Figure 1). Figure 1. Schematic structure of SIVA1 and SIVA2 proteins. The amphipathic helical region (SAH) at the N-terminal region, a death domain homology region (DDHR) in the central section, and a Zinc finger-like (ZF) structure at its C-terminal region are illustrated. The amino acids (aa) positions are indicated.