Antigen: rat liver lysosomal membrane preparations · Clone designation: clone Ly1C6 · Host: mouse · Isotype: IgG₁ · Application(s): WB, IP, and ICC · Lysosome associated membrane protein 1 (LAMP1) and LAMP2 are major constituents of the lysosomal membrane. The two have closely related structures, with 37% sequence homology.¹ They are both transmembrane glycoproteins that are localized primarily in lysosomes and late endosomes. Newly synthesized molecules are mostly transported from the trans-Golgi network directly to endosomes and then to lysosomes. A second pathway involves the LAMPs being delivered from the Golgi to the cell surface, and then along the endocytic pathway to the lysosomes. A minor pathway involves transport via the plasma membrane.² Upon stimulation, a rapid translocation of intracellular LAMPs to the cell membrane is dependent on a carboxyl-terminal tyrosine based motif (YXXI).³ If there is a disturbance in this spacing, lysosome localization of LAMP1 is abolished and the mutant protein then cycles between the membrane and the endosome.² This stimulation has also been shown to have an associated release of histamine, leukotriene C₄ and prostaglandin D₂, which shows that LAMP1 and LAMP2 are activation markers for normal mast cells.³ They have also been linked to the inflammatory response in that they promote adhesion of human peripheral blood mononuclear cells (PBMC) to vascular endothelium and therefore possibly adhesion of PBMC to the site of inflammation.⁴

1 Höning, S., Sandoval, I.V., and von Figura, K. A di-leucine-based motif in the cytoplasmic tail of LIMP-II and tyrosinase mediates selective binding of AP-3. EMBO J 17(5) 1304-1314 (1998).

2 Rohrer, J., Schweizer, A., Russel, D., et al. The targeting of lamp1 to lysosomes is dependent on the spacing of its cytoplasmic tail tyrosine sorting motif relative to the membrane. J Cell Biol 132(4) 565-576 (1996).

3 Grützkau, A., Smorodchenko, A., Lippert, U., et al. LAMP-1 and LAMP-2, but not LAMP-3, are reliable markers for activation-induced secretion of human mast cells. Cytometry A 61(1) 62-68 (2004).

4 Kannan, K., Stewart, R.M., Bounds, W., et al. Lysosome-associated membrane proteins h-LAMP1 (CD107a) and h-LAMP2 (CD107b) are activation-dependent cell surface glycoproteins in human peripheral blood mononuclear cells which mediate cell adhesion to vascular endothelium. Cell Immunol 171(1) 10-19 (1996).

Grützkau, A., Smorodchenko, A., Lippert, U., et al. LAMP-1 and LAMP-2, but not LAMP-3, are reliable markers for activation-induced secretion of human mast cells. Cytometry A 61(1) 62-68 (2004).

Lewis, V., Green, S.A., Marsh, M., et al. Glycoproteins of the lysosomal membrance. J Cell Biol 100 1839-1847 (1985).

Jones, K.A., Jiang, X., Yamamoto, Y., et al. Tuberin is a component of lipid rafts and mediates caveolin-1 localization: Role of TSC2 in post-golgi transport. Exp Cell Res 295(2) 512-524 (2004).

Rohrer, J., Schweizer, A., Russel, D., et al. The targeting of lamp1 to lysosomes is dependent on the spacing of its cytoplasmic tail tyrosine sorting motif relative to the membrane. J Cell Biol 132(4) 565-576 (1996).

Kannan, K., Stewart, R.M., Bounds, W., et al. Lysosome-associated membrane proteins h-LAMP1 (CD107a) and h-LAMP2 (CD107b) are activation-dependent cell surface glycoproteins in human peripheral blood mononuclear cells which mediate cell adhesion to vascular endothelium. Cell Immunol 171(1) 10-19 (1996).

Höning, S., Sandoval, I.V., and von Figura, K. A di-leucine-based motif in the cytoplasmic tail of LIMP-II and tyrosinase mediates selective binding of AP-3. EMBO J 17(5) 1304-1314 (1998).

Show all 6 Hide all but first 3