Family

Lysosome-associated membrane glycoprotein (IPR002000)

Short name: Lysosome-assoc_membr_glycop

Family relationships

None.

Description

Lysosome-associated membrane glycoproteins (lamp) [PMID: 1939168] are integral membrane proteins, specific to lysosomes, and whose exact biological function is not yet clear. Structurally, the lamp proteins consist of two internally homologous lysosome-luminal domains separated by a proline-rich hinge region; at the C-terminal extremity there is a transmembrane region (TM) followed by a very short cytoplasmic tail (C). In each of the duplicated domains, there are two conserved disulphide bonds. This structure is schematically represented in the figure below.

   +-----+            +-----+         +-----+            +-----+
   |     |            |     |         |     |            |     |
  xCxxxxxCxxxxxxxxxxxxCxxxxxCxxxxxxxxxCxxxxxCxxxxxxxxxxxxCxxxxxCxxxxxxxx
  +--------------------------++Hinge++--------------------------++TM++C+

In mammals, there are two closely related types of lamp: lamp-1 and lamp-2, which form major components of the lysosome membrane. In chicken lamp-1 is known as LEP100.

Also included in this entry is the macrophage protein CD68 (or macrosialin) [PMID: 8486654] is a heavily glycosylated integral membrane protein whose structure consists of a mucin-like domain followed by a proline-rich hinge; a single lamp-like domain; a transmembrane region and a short cytoplasmic tail.

Similar to CD68, mammalian lamp-3, which is expressed in lymphoid organs, dendritic cells and in lung, contains all the C-terminal regions but lacks the N-terminal lamp-like region [PMID: 9768752]. In a lamp-family protein from nematodes [PMID: 10862717] only the part C-terminal to the hinge is conserved.

GO terms

Biological Process

No terms assigned in this category.

Molecular Function

No terms assigned in this category.

Cellular Component

GO:0016020 membrane

Contributing signatures

Signatures from InterPro member databases are used to construct an entry.
PANTHER
Pfam
PROSITE profiles
PRINTS