Allosteric regulation of lysosomal enzyme recognition by the cation-independent mannose 6-phosphate receptor

Olson, L. J.; Misra, S.; Ishihara, M.; Battaile, K.; Grant, O.; Sood, A.; Woods, R. J.; Kim, J.-J. P.; Tiemeyer, M.; Ren, G.; Sharp, J.; Dahms, N. M.

doi:10.1101/2020.02.21.959957

bioRxiv · 10.1101/2020.02.21.959957

Allosteric regulation of lysosomal enzyme recognition by the cation-independent mannose 6-phosphate receptor

Olson, L. J.·Misra, S.·Ishihara, M.·Battaile, K.·Grant, O.·Sood, A.·Woods, R. J.·Kim, J.-J. P.·Tiemeyer, M.·Ren, G.·Sharp, J.·Dahms, N. M.

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Abstract

The cation-independent mannose 6-phosphate receptor (CI-MPR), also known as the IGF2 receptor or CD222, is a multifunctional type I transmembrane glycoprotein ubiquitously expressed in most eukaryotic cell types. Through the receptors ability to bind a variety of unrelated extracellular and intracellular ligands, it is involved in a wide array of functions including protein trafficking, lysosomal biogenesis, internalization, regulation of cell growth, cell migration and apoptosis. CI-MPR has a large extracellular region comprised of 15 contiguous domains, four of which interact with phosphorylated glycans on lysosomal enzymes. Here we present a series of biophysical studies, along with crystal structures, providing information on how the N-terminal 5 domains of this receptor work in concert to bind and release carbohydrates. High-resolution electron microscopy as well as hydroxyl radical protein footprinting (HRPF) of this multifunctional multidomain construct demonstrates dynamic conformational changes occur as a consequence of ligand binding and different pH conditions, These data, coupled with surface plasmon resonance studies and molecular modeling, allow us to propose a bi-dentate oligosaccharide binding model, which could explain how high affinity carbohydrate binding is achieved through allosteric domain cooperativity.

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Olson, L. J., Misra, S., Ishihara, M., Battaile, K., Grant, O., Sood, A., Woods, R. J., Kim, J.-J. P., Tiemeyer, M., Ren, G., Sharp, J., Dahms, N. M.. 2020-02-22. Allosteric regulation of lysosomal enzyme recognition by the cation-independent mannose 6-phosphate receptor. https://doi.org/10.1101/2020.02.21.959957

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