Septins are a family of cytoskeletal proteins with GTPase activity involved in various cellular biological processes. Here, we describe the identification of septin 10, a novel septin family member from human dendritic cells. The 3018-bp full-length cDNA potentially encodes a 517-residue peptide, sharing closest homology to human septin 8 and septin 6. With a conserved GTP-binding motif at its N-terminus, septin 10 protein can bind to GTP and exert GTPase activity. Human septin 10 gene is electronically mapped to 8q11.2-12. It is ubiquitously expressed in normal tissues, with the abundant expression in heart and kidney, placenta, skeletal muscles, liver and lung, as well as various tumor cell lines. Interestingly, dendritic cells express upregulated septin 10 upon LPS-induced maturation. Based on its GFP-fusion protein, septin 10 is found to localize in cytoplasm and nucleus, with a subcellular pattern independent of the filamentous state of actin. (C) 2003 Elsevier Science (USA). All rights reserved.