LAMP-1/CD107a 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-1 (lysosome-associated membrane protein 1), also known as CD107a (cluster of differentiation 107a), is a major component of lysosomal membranes that plays an important role in lysosomal biogenesis, autophagy, and cholesterol metabolism (1). LAMP-1 is a type I transmembrane glycoprotein that is expressed on plasma membranes and the membranes of endosomes, autolysosomes, and lysosomes (1,2). Additionally, LAMP-1/CD107a is a commonly used marker for natural killer (NK) cell degranulation (3). LAMP-1 and another lysosomal-associated membrane protein, LAMP-2, together make up about half of all lysosome membrane proteins (1). Additionally, LAMP-1 has a role in presenting carbohydrate ligands to selectins (2). Human LAMP-1 protein is comprised of 417 amino acids (aa) with a theoretical molecular weight of 44.8 kDa; however, glycosylation can increase the molecular weight upwards of 120 kDa (1, 4). Structurally, LAMP-1 protein contains a large luminal/extracellular domain (29-382 aa), a helical transmembrane domain (383-405 aa), and a short cytoplasmic tail (406-417 aa) (1,2). Additionally, the protein has many N- and O-linked glycosylation sites which helps with stability in the membrane (1,2).

LAMP-1 plays an important role in autophagy-mediated ATP-release during apoptosis where lysosomes containing intracellular ATP migrate to the plasma membrane and, during exocytosis, LAMP-1 is exposed to the cell surface (5). Studies have found that knockdown of LAMP-1 blocks the ATP release from the cell (5). Furthermore, an absence of LAMP-1 and LAMP-2 leads to an accumulation of lysosomal cholesterol (6). Lysosomal membrane dysfunction or defects has also been associated with disease development (6,7). For example, one feature of pancreatitis is autophagy impairment which is caused by lysosomal dysfunction and a corresponding decrease in lysosomal-membrane associated proteins LAMP-1 and LAMP-2 (7).

References

1. Eskelinen E. L. (2006). Roles of LAMP-1 and LAMP-2 in lysosome biogenesis and autophagy. Molecular aspects of medicine, 27(5-6), 495-502. https://doi.org/10.1016/j.mam.2006.08.005

2. Cheng, X. T., Xie, Y. X., Zhou, B., Huang, N., Farfel-Becker, T., & Sheng, Z. H. (2018). Revisiting LAMP1 as a marker for degradative autophagy-lysosomal organelles in the nervous system. Autophagy, 14(8), 1472-1474. https://doi.org/10.1080/15548627.2018.1482147

3. Krzewski, K., & Coligan, J. E. (2012). Human NK cell lytic granules and regulation of their exocytosis. Frontiers in immunology, 3, 335. https://doi.org/10.3389/fimmu.2012.00335

4. Uniprot (P11279)

5. Wang, Y., Martins, I., Ma, Y., Kepp, O., Galluzzi, L., & Kroemer, G. (2013). Autophagy-dependent ATP release from dying cells via lysosomal exocytosis. Autophagy, 9(10), 1624-1625. https://doi.org/10.4161/auto.25873

6. Schwake, M., Schr0der, B., & Saftig, P. (2013). Lysosomal membrane proteins and their central role in physiology. Traffic (Copenhagen, Denmark), 14(7), 739-748. https://doi.org/10.1111/tra.12056

7. Gukovsky, I., Pandol, S. J., Mareninova, O. A., Shalbueva, N., Jia, W., & Gukovskaya, A. S. (2012). Impaired autophagy and organellar dysfunction in pancreatitis. Journal of gastroenterology and hepatology, 27 Suppl 2(Suppl 2), 27-32. https://doi.org/10.1111/j.1440-1746.2011.07004.x

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 NBP2-07733

• LAMP-1/CD107a Antibodies
• LAMP-1/CD107a Antibody Pair
• LAMP-1/CD107a ELISA Kits
• LAMP-1/CD107a Lysate
• LAMP-1/CD107a Proteins
• LAMP-1/CD107a Proteins and Enzymes