Heat shock protein, Hsp90 plays a role in MT1-MMP's ability to activate substrate proteins

Abstract

Membrane type 1 matrix metalloproteinase (MT1-MMP) plays a major role in cancer invasion and metastasis. The mechanism by which MT1-MMP is trafficked to the plasma membrane where it functions to proteolytically activate its substrate proteins is not fully understood. The gene of heat shock protein (Hsp90alpha) was identified as being upregulated in HT1080 cells treated with concanavalin A (conA), a lectin that promotes proMMP-2 activation and cell migration in HT1080 cells compared to untreated HT1080 cells. To determine the mechanism underlying MT1-MMP substrate degradation and cell migration, biological and biochemical approaches were carried out. Zymography was preformed to examine the affect of the presence of both Hsp90alpha; and MT1-MMP, on the gelatinase activity of matrix metalloproteinase (MMP-2). The zympograph showed that when both Hsp90alpha and MT1-MMP were both present, there was an increase in the active form of MMP-2, a protein that is proteolytically activated by MT1-MMP at the plasma membrane. shRNA knockdown studies of Hsp90alpha were also done to further establish a role for Hsp90alpha in effecting the ability of MT1-MMP to activate its target proteins at the plasma membrane. Together these studies indicate that Hsp90alpha plays a role in the ability of MT1-MMP to activate substrate proteins at the plasma membrane.