Cloning and genomic characterization of sytdep, a new synaptotagmin XIV-related gene

We have identified a new human gene coined sytdep (synaptotagmin XIV-derived protein) in human neutrophils. Sytdep encodes a 188-amino acid sequence with a 21.435 kDa deduced molecular mass, showing 75% identity to human synaptotagmin (syt) XIV. Human neutrophils express sytdep, but not syt XIV. Sytdep was upregulated during HL-60 neutrophil differentiation. Sytdep gene is located in human chromosome 4 and contains a unique exon, whereas syt XIV gene, located in chromosome 1, comprises 10 exons with 9 introns. Mouse genome did not contain sytdep. The N-terminal region of sytdep shows no homology with any known protein and, unlike synaptotagmin XIV isoforms, sytdep shows a unique C-terminal C2B domain. Polyclonal antibodies against the C2B domain of syt XIV recognized sytdep as a 27-kDa protein in human neutrophils. Genomic analyses suggest that human sytdep could derive from a retrotranslocation of a syt XIV transcript into chromosome 4. © 2005 Elsevier Inc. All rights reserved.This work was supported by grants from the Fondo de Investigación Sanitaria and European Commission (FIS-FEDER 04/0843, 02/1199, and 01/1048), Ministerio de Educación y Ciencia (SAF2005-04293), Fundación de Investigación Médica Mutua Madrileña (FMM), Fundación ‘‘la Caixa’’ (BM05-30-0), and Junta de Castilla y León (CSI04A05).Peer Reviewe