Inhibitory role of TACE/ADAM17 cytotail in protein ectodomain shedding

• 作者: Liliana Pérez
• 来源期刊: 世界生物化学杂志：英文版（电子版）
• 学科: 医学
• 关键词: ADAM17 ECTODOMAIN SHEDDING L-SELECTIN Tumor necrosis factor-α CONVERTING enzyme
• 年，卷（期）: 2011,（11）
• 页码范围: 246-251
• 页数: 6页
• 分类号: R363

摘要

AIM:To determine if the cytotail of the principal sheddase tumor necrosis factor-α converting enzyme (TACE;ADAM17) controls protein ectodomain shedding.METHODS:Site-directed mutagenesis was performed to derive TACE variants. The resulting TACE expression plasmids with amino acid substitutions in the extracel-lular,cysteine-rich disintegrin domain (CRD) and/or deleted cytotail,along with an expression vector for the enhanced green fluorescence protein were transfected into shedding-defective M1 mutants stably expressing transmembrane L-selectin or transforming growth factor (TGF)-α. The expression levels of the TACE substrates at the cell surface were determined by flow cytometry. RESULTS:Consistent with published data,a single point mutation (C600Y) in the CRD led to shedding defi-ciency. However,removal of the cytotail from the C600Y TACE variant partially restored ectodomain cleavage of TGF-α and L-selectin. Cytotail-deleted mutants with any other substituting amino acid residues in place of Cys600 displayed similar function compared with tail-less C600Y TACE.CONCLUSION:The cytotail plays an inhibitory role,which becomes evident when it is removed from an enzyme with another mutation that affects the enzyme function.