Human procathepsin B interacts with the annexin II tetramer on the surface of tumor cells.
To study potential roles of plasma membrane-associated extracellular cathepsin B in tumor cell invasion and metastasis, we used the yeast two-hybrid system to screen for proteins that interact with human procathepsin B. The annexin II light chain (p11), one of the two subunits of the annexin II tetramer, was one of the proteins identified. We have confirmed that recombinant human procathepsin B interacts with p11 as well as with the annexin II tetramer in vitro. Furthermore, procathepsin B could interact with the annexin II tetramer in vivo as demonstrated by coimmunoprecipitation. Cathepsin B and the annexin II tetramer were shown by immunofluorescent staining to colocalize on the surface of human breast carcinoma and glioma cells. Taken together, our results indicate that the annexin II tetramer can serve as a binding protein for procathepsin B on the surface of tumor cells, an interaction that may facilitate tumor invasion and metastasis.
Mai
J
J
Department of Pharmacology, Wayne State University, School of Medicine, Detroit, Michigan 48201, USA.
Finley
R L
RL
Waisman
D M
DM
Sloane
B F
BF
D017306:Annexin A2 / Q000737:chemistry / Q000378:metabolism*; D002401:Cathepsin B / Q000378:metabolism*; D002462:Cell Membrane / Q000378:metabolism; D018076:DNA, Complementary / Q000378:metabolism; D004792:Enzyme Precursors / Q000378:metabolism*; D015723:Gene Library; D005982:Glutathione Transferase / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000378:metabolism; D018613:Microscopy, Confocal; D016296:Mutagenesis; D010957:Plasmids / Q000378:metabolism; D011233:Precipitin Tests; D011485:Protein Binding; D011487:Protein Conformation; D011993:Recombinant Fusion Proteins; D014407:Tumor Cells, Cultured; D020798:Two-Hybrid System Techniques
D017306:Annexin A2; D018076:DNA, Complementary; D004792:Enzyme Precursors; D008565:Membrane Proteins; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; C057832:procathepsin B; D002401:Cathepsin B