LAMP-2/CD107b Overexpression Lysate

HEK293T cells in 10-cm dishes were transiently transfected with a non-lipid polymer transfection reagent specially designed and manufactured for large volume DNA transfection. Transfected cells were cultured for 48hrs before collection. The cells were lysed in modified RIPA buffer (25mM Tris-HCl pH7.6, 150mM NaCl, 1% NP-40, 1mM EDTA, 1xProteinase inhibitor cocktail mix, 1mM PMSF and 1mM Na3VO4, and then centrifuged to clarify the lysate. Protein concentration was measured by BCA protein assay kit.

LAMP-2 (Lysosome-associated membrane protein 2) is a single-pass type I membrane protein that belongs to a family of membrane glycoproteins (~40 KDa). LAMP-2 protein is encoded by nine exons, with the first 8 exons and a portion of exon 9 encoding the highly glycosylated protein domains within the lysosomal lumen. The transmembrane and cytosolic carboxy-terminal domains of LAMP-2 are encoded by the remaining sequence of exon 9 and conform the receptor for targeting proteins to the lysosome. Splicing of exon 9 in the LAMP-2 pre mRNA leads to various splice forms with distinct cytosolic domains. Three splice variants, LAMP-2A, -2B and -2C, have been identified which shuttle between the plasma membrane, endosomal compartment and lysosomes (1). Tissue specific expression has been described for each LAMP-2 splice variant, with LAMP-2A being more ubiquitously expressed (e.g., placenta, lung, liver, pancreas and prostate), LAMP-2B predominantly expressed in skeletal muscle and LAMP-2C in brain tissue (1). All LAMP-2 splice variants participate in lysosomal degradation processes. LAMP-2A is the only variant that serves as a receptor targeting proteins for lysosomal degradation in chaperone-mediated autophagy (2,3). LAMP-2B is essential for macroautophagy in cardiomyocytes, where it facilitates autophagosome-lysosome fusion. LAMP-2B mutations underscore the myopathy and severe hypertrophic cardiomyopathy in Danon disease which results from deficits in autophagy (1, 4). Vasculopathy of coronary and cerebral arteries is a rare phenotype in Danon patients that is also associated with deficient autophagy processing of proteins and cellular organelles (5). LAMP2C serves as a receptor for DNA and RNA, facilitating their lysosomal degradation through DNA-autophagy and RNA-autophagy, respectively (1).

References

1. Rowland, T. J., Sweet, M. E., Mestroni, L., & Taylor, M. R. G. (2016). Danon disease - dysregulation of autophagy in a multisystem disorder with cardiomyopathy. Journal of Cell Science. https://doi.org/10.1242/jcs.184770

2. Alfaro, I. E., Albornoz, A., Molina, A., Moreno, J., Cordero, K., Criollo, A., & Budini, M. (2019). Chaperone mediated autophagy in the crosstalk of neurodegenerative diseases and metabolic disorders. Frontiers in Endocrinology. https://doi.org/10.3389/fendo.2018.00778

3. Schneider, J. L., & Cuervo, A. M. (2014). Autophagy and human disease: Emerging themes. Current Opinion in Genetics and Development. https://doi.org/10.1016/j.gde.2014.04.003

4. Chi, C., Leonard, A., Knight, W. E., Beussman, K. M., Zhao, Y., Cao, Y., Song, K. (2019). LAMP-2B regulates human cardiomyocyte function by mediating autophagosome lysosome fusion. Proceedings of the National Academy of Sciences of the United States of America. https://doi.org/10.1073/pnas.1808618116

5. Nguyen, H. T., Noguchi, S., Sugie, K., Matsuo, Y., Nguyen, C. T. H., Koito, H., Tsukaguchi, H. (2018). Small-Vessel Vasculopathy Due to Aberrant Autophagy in LAMP-2 Deficiency. Scientific Reports. https://doi.org/10.1038/s41598-018-21602-8

This product is for research use only and is not approved for use in humans or in clinical diagnosis. Lysates are guaranteed for 6 months from date of receipt.

Array NBP2-08128

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