TY - JOUR
T1 - DNA accelerates the inhibition of human cathepsin V by serpins
AU - Ong, Poh Chee
AU - McGowan, Sheena
AU - Pearce, Mary C.
AU - Irving, James A.
AU - Kan, Wan Ting
AU - Grigoryev, Sergei A.
AU - Turk, Boris
AU - Silverman, Gary A.
AU - Brix, Klaudia
AU - Bottomley, Stephen P.
AU - Whisstock, James C.
AU - Pike, Robert N.
PY - 2007/12/21
Y1 - 2007/12/21
N2 - A balance between proteolytic activity and protease inhibition is crucial to the appropriate function of many biological processes. There is mounting evidence for the presence of both papain-like cysteine proteases and serpins with a corresponding inhibitory activity in the nucleus. Well characterized examples of cofactors fine tuning serpin activity in the extracellular milieu are known, but such modulation has not been studied for protease-serpin interactions within the cell. Accordingly, we present an investigation into the effect of a DNA-rich environment on the interaction between model serpins (MENT and SCCA-1), cysteine proteases (human cathepsin V and human cathepsin L), and cystatin A. DNA was indeed found to accelerate the rate at which MENT inhibited cathepsin V, a human orthologue of mammalian cathepsin L, up to 50-fold, but unexpectedly this effect was primarily effected via the protease and secondarily by the recruitment of the DNA as a "template" onto which cathepsin V and MENT are bound. Notably, the protease-mediated effect was found to correspond both with an altered substrate turnover and a conformational change within the protease. Consistent with this, cystatin inhibition, which relies on occlusion of the active site rather than the substrate-like behavior ofserpins, was unaltered by DNA. This represents the first example of modulation of serpin inhibition of cysteine proteases by a cofactor and reveals a mechanism for differential regulation of cathepsin proteolytic activity in a DNA-rich environment.
AB - A balance between proteolytic activity and protease inhibition is crucial to the appropriate function of many biological processes. There is mounting evidence for the presence of both papain-like cysteine proteases and serpins with a corresponding inhibitory activity in the nucleus. Well characterized examples of cofactors fine tuning serpin activity in the extracellular milieu are known, but such modulation has not been studied for protease-serpin interactions within the cell. Accordingly, we present an investigation into the effect of a DNA-rich environment on the interaction between model serpins (MENT and SCCA-1), cysteine proteases (human cathepsin V and human cathepsin L), and cystatin A. DNA was indeed found to accelerate the rate at which MENT inhibited cathepsin V, a human orthologue of mammalian cathepsin L, up to 50-fold, but unexpectedly this effect was primarily effected via the protease and secondarily by the recruitment of the DNA as a "template" onto which cathepsin V and MENT are bound. Notably, the protease-mediated effect was found to correspond both with an altered substrate turnover and a conformational change within the protease. Consistent with this, cystatin inhibition, which relies on occlusion of the active site rather than the substrate-like behavior ofserpins, was unaltered by DNA. This represents the first example of modulation of serpin inhibition of cysteine proteases by a cofactor and reveals a mechanism for differential regulation of cathepsin proteolytic activity in a DNA-rich environment.
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U2 - 10.1074/jbc.M706991200
DO - 10.1074/jbc.M706991200
M3 - Article
C2 - 17923478
AN - SCOPUS:37549070361
SN - 0021-9258
VL - 282
SP - 36980
EP - 36986
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 51
ER -