TY - JOUR
T1 - Hepatocyte adhesion to carbohydrate-derivatized surfaces. I. Surface topography of the rat hepatic lectin
AU - Weisz, Ora A.
AU - Schnaar, Ronald L.
PY - 1991/10
Y1 - 1991/10
N2 - The rat hepatic lectins, galactose- and N-acetylgalactosamine-binding proteins found on the hepatocyte cell surface, mediate adhesion of isolated primary rat hepatocytes to artificial galactose-derivatized polyacrylamide gels. Biochemical and immunohistochemical techniques were used to examine the topographical redistribution of the rat hepatic lectins in response to galactose-mediated cell adhesion. Hepatocytes isolated from rat liver by collagenase perfusion had an average of 7 × 105 cell surface lectin molecules per cell, representing 30-50% of the total lectin molecules per cell, the remainder residing in intracellular pools. Hepatocytes incubated on galactose-derivatized surfaces, whether at 0-4°C or 37°C, rapidly lost >80% of their accessible cell surface lectin binding sites into an adhesive patch of characteristic morphology. The kinetics of rat hepatic lectin disappearance were used to estimate a lateral diffusion coefficient of >9 × 10~9 cm2/s at 37°C, suggesting rapid and unimpeded lectin diffusion in the plane of the membrane. Indirect immunofluorescence labeling of adherent cells using antihepatic lectin antibody revealed a structured ring of receptors surrounding an area of exclusion (patch) of reproducible size and shape which represented ∼8% of the hepatocyte cell surface. Notably, adherent cells, which had lost >80% of their accessible surface binding sites, still endocytosed soluble galactose-terminated radioligand at >50% of the rate of nonadherent control cells. No net movement of rat hepatic lectin from intracellular pools to the cell surface was found on cells recovered after adhesion to galactose-derivatized surfaces at 37°C, suggesting that the physical size and/or lectin density of the patch was restricted by kinetic or topological constraints.
AB - The rat hepatic lectins, galactose- and N-acetylgalactosamine-binding proteins found on the hepatocyte cell surface, mediate adhesion of isolated primary rat hepatocytes to artificial galactose-derivatized polyacrylamide gels. Biochemical and immunohistochemical techniques were used to examine the topographical redistribution of the rat hepatic lectins in response to galactose-mediated cell adhesion. Hepatocytes isolated from rat liver by collagenase perfusion had an average of 7 × 105 cell surface lectin molecules per cell, representing 30-50% of the total lectin molecules per cell, the remainder residing in intracellular pools. Hepatocytes incubated on galactose-derivatized surfaces, whether at 0-4°C or 37°C, rapidly lost >80% of their accessible cell surface lectin binding sites into an adhesive patch of characteristic morphology. The kinetics of rat hepatic lectin disappearance were used to estimate a lateral diffusion coefficient of >9 × 10~9 cm2/s at 37°C, suggesting rapid and unimpeded lectin diffusion in the plane of the membrane. Indirect immunofluorescence labeling of adherent cells using antihepatic lectin antibody revealed a structured ring of receptors surrounding an area of exclusion (patch) of reproducible size and shape which represented ∼8% of the hepatocyte cell surface. Notably, adherent cells, which had lost >80% of their accessible surface binding sites, still endocytosed soluble galactose-terminated radioligand at >50% of the rate of nonadherent control cells. No net movement of rat hepatic lectin from intracellular pools to the cell surface was found on cells recovered after adhesion to galactose-derivatized surfaces at 37°C, suggesting that the physical size and/or lectin density of the patch was restricted by kinetic or topological constraints.
UR - http://www.scopus.com/inward/record.url?scp=0026039788&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0026039788&partnerID=8YFLogxK
U2 - 10.1083/jcb.115.2.485
DO - 10.1083/jcb.115.2.485
M3 - Article
C2 - 1655806
AN - SCOPUS:0026039788
SN - 0021-9525
VL - 115
SP - 485
EP - 493
JO - Journal of Cell Biology
JF - Journal of Cell Biology
IS - 2
ER -