Molecular cloning and characterization of a novel inhibitor of apoptosis protein from Xenopus laevis

• Published in: Biochemical and biophysical research communications Vol. 301; no. 1; pp. 236 - 242
• Main Authors: Song, Kwang-Hoon, Kim, Tae-Moon, Kim, Han-Jong, Kim, Jung Woo, Kim, Hong-Hee, Kwon, Hyuk-Bang, Kim, Won Sun, Choi, Hueng-Sik
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 31.01.2003
• Subjects: Amino Acid Sequence; Animals; Base Sequence; Cloning, Molecular; Cysteine Proteinase Inhibitors - genetics; Embryo, Nonmammalian - anatomy & histology; Embryo, Nonmammalian - physiology; Humans; In Situ Hybridization; Inhibitor of Apoptosis Proteins; Insect Proteins - genetics; Insect Proteins - metabolism; Microtubule-Associated Proteins - genetics; Molecular Sequence Data; Neoplasm Proteins; Protein Binding; Proteins; Receptors, Retinoic Acid - metabolism; Retinoid X Receptors; Sequence Alignment; Survivin; Tissue Distribution; Transcription Factors - metabolism; Two-Hybrid System Techniques; Xenopus laevis; Xenopus laevis - physiology; Xenopus Proteins - genetics; Xenopus Proteins - metabolism
• ISSN: 0006-291X; 1090-2104
• DOI: 10.1016/S0006-291X(02)03013-9

A novel inhibitor of apoptosis protein family member termed SIX was identified in Xenopus containing a single baculoviral IAP repeat (BIR) domain and no COOH-terminal RING finger domain. It exhibited striking amino acid sequence similarity with human survivin, mouse TIAP, and recently found Xenopus survivin, especially a part of BIR domain was highly conserved. Interestingly, SIX interacted with RXRα through the AF2 domain in the absence of ligand, which was weakened when the ligand was present. Northern blot analysis demonstrated that SIX mRNA was not detectable in adult with exception of the ovary and testis, and whole-mount in situ hybridization and Northern blot analyses revealed strong and homogeneous expression of SIX in the developing oocytes. In the embryos, the expression of SIX was observed in the animal hemisphere from one-cell to yolk plug stages and high level of expression was detected in the future brain and dorsal region of the neural tube at the neurula stage and early tail-bud stage. These results strongly support the fact that survivin is evolutionarily conserved in structure and SIX is likely to be the Xenopus counterpart of human and mouse survivin.