Chaperone-mediated autophagy (CMA) is a selective type of autophagy by which 
specific cytosolic proteins are sent to lysosomes for degradation. Substrate 
proteins bind to the lysosomal membrane through the lysosome-associated membrane 
protein type 2A (LAMP-2A), one of the three splice variants of the lamp2 gene, 
and this binding is limiting for their degradation via CMA. However, the 
mechanisms of substrate binding and uptake remain unknown. We report here that 
LAMP-2A organizes at the lysosomal membrane into protein complexes of different 
sizes. The assembly and disassembly of these complexes are a very dynamic 
process directly related to CMA activity. Substrate proteins only bind to 
monomeric LAMP-2A, while the efficient translocation of substrates requires the 
formation of a particular high-molecular-weight LAMP-2A complex. The two major 
chaperones related to CMA, hsc70 and hsp90, play critical roles in the 
functional dynamics of the LAMP-2A complexes at the lysosomal membrane. Thus, we 
have identified a novel function for hsc70 in the disassembly of LAMP-2A from 
these complexes, whereas the presence of lysosome-associated hsp90 is essential 
to preserve the stability of LAMP-2A at the lysosomal membrane.