CD62L SELL (selection L, lymphocyte adhesion molecule 1),  LAM-1(lymphocyte adhesion molecule), MEL-14 (mouse)
Molecule TypeAntigen ExpressionMolecular Weight
Min / Max
Non-lineage Restricted Molecule
Type 1 glycoprotein
Hematopoietic Cell
Monocyte
NK Cell
Myeloid Cell
Peripheral blood
Thymocyte
Neutrophil
Spleen
Lymphocyte
Blood Cell
Granulocyte
Bone Marrow
T Cell
Malignant cell
B Cell
65 / 65
74 / 74
94 / 94

Expression
CD62L is expressed on most peripheral blood B and T cells, monocytes and granulocytes.  CD62L is expressed on some NK cells and spleen lymphocytes, bone marrow lymphocytes, bone marrow myeloid cells, thymocytes and on certain hematopoietic malignant cells.  The majority of B cells and naive T cells express CD62L but only subpopulations of memory T and NK cells are CD62L positive.  Subpopulations of immature and mature thymocytes express CD62L.  CD62L is rapidly lost upon activation of lymphocytes and neutrophils as a result of proteolytic cleavage.  A soluble form of CD62L is present at high levels in the blood.


Structure
MOLECULAR FAMILY NAME: Belongs to the selectin C-type lectin family.

CD62L is a single-pass type-1 334 aa glycoprotein.  It contains a 279 aa extracellular domain which contains a N-terminal C-type domain, a epidermal growth factor (EGF) domain, 2 complement control binding protein (CCP) domains and a 15 aa spacer between the CCP domain and the transmembrane domain which contains a proteolytic cleavage site (Lys283 and Ser284), a 23 aa transmembrane domain and a 17 aa short intracellular cytoplasmic domain which bears no sequence similarity to the cytoplasmic domains of CD62P or CD62E but is highly conserved across species.  It is a member of the selectin family of cell surface molecules, which includes CD62E and CD62P.  

MOLECULAR MASS
Cell Type Unreduced Reduced Comment
Neutrophil 94 kDa
Lymphocyte 65 kDa 74 kDa

POST-TRANSCRIPTIONAL MODIFICATION: No information.

POST-TRANSLATIONAL MODIFICATION

There are 7 possible N-linked glycosylation sites present in the extracellular region.  CD62L is endoproteolytically cleaved from the cell surface at a membrane-proximal extracellular site, K268-S269, which is 11 aa away from the membrane-spanning domain.

Ligands
Like CD62E and CD62P, CD62L binds with a low affinity to anionic oligosaccharide sequences related to sialylated Lewis x (sLe x, CD15s) through its C-type lectin domain.  CD62P and CD62L also bind various structurally unrelated anionic carbohydrates such as heparin sulfate (HS) and sulfatides. CD62L binds particularly well to carbohydrates present on certain glycoforms of CD34, GlyCAM-1 and MAdCAM-1.  The precise nature of these high affinity carbohydrate ligands is not know but binding requires fucosylation, sialylation and sulfation, suggesting a role for structures related to sulfated sLe x.  CD62L also binds CD162 PSGL-1. The 11 C-terminal residues of the 17 aa cytoplasmic domain which are essential for CD62L adhesion, mediate association with a complex of cytoskeletal proteins which includes a -actinin.  These residues are not required for localization of CD62L to microvilli.

LIGANDS AND MOLECULES ASSOCIATED WITH CD62L
Molecule Comment
CD34
CD62L binds a series of heavily glycosylated, fucosylated, sulfated sialylated glycoproteins that include CD34, GlyCAM-1 and MAdCAM-1.

GlyCAM-1
CD62L binds a series of heavily glycosylated, fucosylated, sulfated sialylated glycoproteins that include CD34, GlyCAM-1 and MAdCAM-1.

MAdCAM-1 CD62L binds a series of heavily glycosylated, fucosylated, sulfated sialylated glycoproteins that include CD34, GlyCAM-1 and MAdCAM-1.




Function
CD62L mediates lymphocyte homing to high endothelial venules of peripheral lymphoid tissue and leukocyte rolling on activated endothelium, a precursor to extravasation during inflammation.  Like other selectins, CD62L mediates the initial tethering and rolling of leukocytes on endothelial surfaces, which is a prerequisite for leukocyte extravasation from the blood into tissues.  More specifically, CD62L is important for the homing of naive lymphocytes via high endothelial venules to peripheral lymph nodes and Peyer's patches.  CD62L also contributes, along with other selectins, to the recruitment of leukocytes from the blood to areas of inflammation.  Unlike CD62P, CD62L contributes mainly to the later recruitment after 1 hour  presumably due to delay in the induction of suitable endothelial ligands.  The localization of CD62L to the tips of surface microvilli is required for optimal CD62L-mediated attachment and rolling under flow.  CD62L can also mediate neutrophil-neutrophil interactions through recognition of CD162.  Ligation of CD62L can stimulate its proteolytic release from the cell, which may be important for high rolling velocities.  Ligation of CD62L on T cells with soluble GlyCAM-1 stimulates adhesion through b2 CD18 integrins.  CD62L-/- mice cannot be tolerized and adoptive transfer of their cells prevents tolerization in wild-type mice.  This effect is due to the inability of CD62- T cells to reach lymph nodes and other lymphoid organs that are tolerogenic environments. 

BIOCHEMICAL ACTIVITY: No information.

DISEASE RELEVANCE AND FUNCTION OF CD62L IN INTACT ANIMAL

CD62L is a potential target for the treatment of chronic inflammatory diseases such as asthma.  Soluble CD62L is released by proteolysis during inflammation and serum CD62L is thus an indicator of inflammation.

Comments
MOLECULAR INTERACTIONS -
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD62L: No information.

SUBSTRATES: No information.

ENZYMES WHICH MODIFY CD62L: No information.


Database accession numbers
AnimalPIRSWISSPROTEMGBL/GENBANK
 
HumanEntrezgene 6402P14151
MouseA32375P18337M36005
RatS23936P30836D10831
Antibodies
BAQ92A   View Reactivity
CC32   View Reactivity
DREG 56   View Reactivity
DU1-29   View Reactivity
FMC46   View Reactivity
SK11   View Reactivity

Revised June 25, 2008


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