Lysosomal-associated membrane glycoprotein-1 precursor, LAMP-1 (stabilizes TAPL (TC# 3.A.1.209.2) (Demirel et al., 2012). Human LAMP1 accelerates Lassa virus fusion and potently promotes fusion pore dilation upon forcing viral fusion with non-endosomal membrane (Zhang et al. 2022). Ectopic expression of hLAMP1 accelerated the kinetics of small fusion pore formation.  The Ykt6-Snap29-Syx13 SNARE complex promotes crinophagy via secretory granule fusion with Lamp1 carrier vesicles (Szenci et al. 2024).  The acidic pH of lysosomes is critical for catabolism in eukaryotic cells and is altered in neurodegenerative disease including Alzheimer's and Parkinson's. Reports using Drosophila and mammalian cell cultures have identified novel and, at first sight, conflicting roles for the lysosomal associated membrane proteins (LAMPs) in the regulation of the endolysosomal system (Handy et al. 2024). 

Animals

LAMP1 of Homo sapiens (P11279)

Lysosomal-associated membrane protein 2 precursor, LAMP2a. LAMP2 colocalizes with TM7SF1 (GRP137B) (TC#9.B.123.1.1) (Gao et al., 2012).  A comparative study of the steady-state subcellular distribution of LAMP-2 isoforms with GYXXPhi-type tyrosine-based motifs that interact differently with four adaptor protein (AP) complexes has appeared (Yamaguchi et al. 2023). LAMP-2A-CT interacts with all four mu-subunits (mu1, mu2, mu3A, and mu4 of AP-1, AP-2, AP-3, and AP-4, respectively). The interaction with mu3A is more robust than that with other mu-subunits. LAMP-2B-CT interacts exclusively and moderately with mu3A and did not detectably interact with any of the four mu-subunits. All isoforms localize to late endosomes and lysosomes (Yamaguchi et al. 2023).

Metazoa

LAMP2a of Homo sapiens (410 aas; 2 TMSs) (P13473)

Lysosome-associated membrane glycoprotein 1-like protein of 318 aas and 2 TMSs, N- and C-terminal.

LAMP1 of Hyalella azteca

Uncharacterized protein of 306 aas and 2 TMSs, N- and C-terminal.

UP of Trachymyrmex cornetzi

Lysosome-associated membrane glycoprotein 5, LAMP, of 281 aas and 2 TMSs, N- and C-terminal.

LAMP5 of Protobothrops mucrosquamatus

Macrosialin of 418 aas and 2 TMSs.

Macrosialin of Balaenoptera acutorostrata scammoni

Uncharacterized protein of 242 aas and 2 TMSs, N- and C-terminal

UP of Oryzias melastigma

LAMP1 (LAMP, dLAMP) of 318 aas and 2 TMSs, N- and C-terminal. The endolysosomal system not only is an integral part of the cellular catabolic machinery that processes and recycles nutrients for synthesis of biomaterials, but it also acts as signaling hub to sense and coordinate the energy state of cells with growth and differentiation. Lysosomal dysfunction adversely influences vesicular transport-dependent macromolecular degradation and thus causes serious problems for human health. In mammalian cells, loss of the lysosome associated membrane proteins, LAMP1 and LAMP2, strongly affects autophagy and cholesterol trafficking. Chaudhry et al. 2022 showed that Drosophila Lamp1 is a bona fide ortholog of vertebrate LAMP1 and LAMP2. Surprisingly and in contrast to lamp1 lamp2 double-mutant mice, Drosophila Lamp1 is not required for viability or autophagy, suggesting that fly and vertebrate LAMP proteins acquired distinct functions.

LAMP1 of Drosophila melanogaster (Fruit fly)

Lysosome-associated membrane glycoprotein 3. LAMP3, of 416 aas and 2 TMSs, N- and C-terminal.   It plays a role in the unfolded protein response that contributes to protein degradation and cell survival during proteasomal dysfunction (Dominguez-Bautista et al. 2015). It plays a role in the process of fusion of the lysosome with the autophagosome, thereby modulating the autophagic process (Nagelkerke et al. 2014). It supports the FURIN-mediated cleavage of mumps virus fusion protein F by interacting with both FURIN and the unprocessed form but not the processed form of the viral protein F (Ueo et al. 2020). It also plays a positive role in post-entry steps of influenza A virus replication (Zhou et al. 2011), and it promotes nuclear accumulation of influenza nucleoprotein/NP at early stages of viral infection while promoting the intracellular proliferation of Salmonella typhimuium.(Ueo et al. 2020). 

LAMP3 of Homo sapiens