Description
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
Bioinformatics
Entrez |
Mouse Rat Human |
Uniprot |
Human Human Human Human Mouse |
Product By Gene ID |
3920 |
Alternate Names |
- CD107 antigen-like family member B
- CD107b antigen
- CD107b
- LAMP2
- LAMP-2
- LAMP2A
- LAMP-2A
- LAMPB
- LGP110
- LGP-96
- Lysosomal Associated Membrane Protein 2
- lysosomal-associated membrane protein 2
- lysosome-associated membrane glycoprotein 2
- Lysosome-associated membrane protein 2
|