Peptide aptamers as new tools to modulate clathrin-mediated internalisation--inhibition of MT1-MMP internalisation.
BACKGROUND
Peptide aptamers are combinatorial protein reagents that bind to targets with a high specificity and a strong affinity thus providing a molecular tool kit for modulating the function of their targets in vivo.


RESULTS
Here we report the isolation of a peptide aptamer named swiggle that interacts with the very short (21 amino acid long) intracellular domain of membrane type 1-metalloproteinase (MT1-MMP), a key cell surface protease involved in numerous and crucial physiological and pathological cellular events. Expression of swiggle in mammalian cells was found to increase the cell surface expression of MT1-MMP by impairing its internalisation. Swiggle interacts with the LLY573 internalisation motif of MT1-MMP intracellular domain, thus disrupting the interaction with the mu2 subunit of the AP-2 internalisation complex required for endocytosis of the protease. Interestingly, swiggle-mediated inhibition of MT1-MMP clathrin-mediated internalisation was also found to promote MT1-MMP-mediated cell migration.


CONCLUSIONS
Taken together, our results provide further evidence that peptide aptamers can be used to dissect molecular events mediated by individual protein domains, in contrast to the pleiotropic effects of RNA interference techniques.
Wickramasinghe
Rochana D
RD
Department of Oncology, Cambridge Research Centre, University of Cambridge, Cambridge CB2 0RE, UK.
Ko Ferrigno
Paul
P
Roghi
Christian
C
D033962:Adaptor Protein Complex 2 / Q000378:metabolism*; D020816:Amino Acid Motifs; D052158:Aptamers, Peptide / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D002966:Clathrin / Q000378:metabolism; D004705:Endocytosis / Q000187:drug effects; D006801:Humans; D053511:Matrix Metalloproteinase 14 / Q000378:metabolism*; D011485:Protein Binding / Q000187:drug effects; D017434:Protein Structure, Tertiary; D052156:SELEX Aptamer Technique
D033962:Adaptor Protein Complex 2; D052158:Aptamers, Peptide; D002966:Clathrin; D053511:Matrix Metalloproteinase 14