Brief Article
Copyright ©2011 Baishideng Publishing Group Co., Limited. All rights reserved.
World J Biol Chem. Nov 26, 2011; 2(11): 246-251
Published online Nov 26, 2011. doi: 10.4331/wjbc.v2.i11.246
Inhibitory role of TACE/ADAM17 cytotail in protein ectodomain shedding
Xiaojin Li, Liliana Pérez, Huizhou Fan
Xiaojin Li, Liliana Pérez, Huizhou Fan, Department of Physiology and Biophysics, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, Piscataway, NJ 08854, United States
Author contributions: Fan H conceived the study; all authors were involved in experimental design; Li X and Pérez L performed the experiments; Fan H, Li X and Pérez L analyzed the data; Fan H wrote the manuscript.
Supported by Grants from the National Institutes of Health, No. AG029859; the National Center of the American Heart Association, No. 0330335N; the New Jersey Commission on Cancer Research (NJCCR 703010) to Fan H
Correspondence to: Huizhou Fan, MD, PhD, Department of Physiology and Biophysics, Robert Wood Johnson Medical School, University of Medicine and Dentistry of New Jersey, 683 Hoes Lane West, Piscataway, NJ 08854, United States. fanhu@umdnj.edu
Telephone: +1-732-2354607 Fax: +1-732-2355038
Received: August 22, 2011
Revised: October 12, 2011
Accepted: October 19, 2011
Published online: November 26, 2011
Abstract

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 extracellular, 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 deficiency. 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.

Keywords: ADAM17; Ectodomain shedding; L-selectin; Tumor necrosis factor-α converting enzyme