N-cadherin of the human lens.
N-cadherin was identified in the human lens by its immunological specificity, and concanavalin-A (Con-A) binding. The 135 kd glycoprotein was partially purified from human lens plasma membranes by Con-A affinity column chromatography. In the newborn lens, N-cadherin is distributed equally in amount between cortical and nuclear membranes. It is markedly decreased in the nuclear membranes of the 2 year-old lens and was no longer detectable in the nucleus of 15 yr-old and older lenses (15 yrs - 86 yrs). Such nuclear loss of N-cadherin is consistent with similar findings in the chicken and bovine lens. At all ages, N-cadherin was readily detected in cortical fiber-cells. When expressed as a ratio to MP26 content, the amount of N-cadherin of the total fiber mass declines at least 4-fold from newborn to 15 years of age, and remains stable thereafter. Homogenization of bovine lenses in the presence of Ca++ resulted in a marked loss of the protein, suggestive of degradation by a calcium-activated protease. The loss of N-cadherin with aging in fiber cells suggests either an alteration in the mode of membrane adhesion of these cells, or a decline in adhesiveness of nuclear as compared to cortical fiber-cells.
Atreya
P L
PL
Department of Anatomy and Cell Biology, Wayne State University, School of Medicine, Detroit, MI 48201.
Barnes
J
J
Katar
M
M
Alcala
J
J
Maisel
H
H
D000293:Adolescent; D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism; D000818:Animals; D015820:Cadherins / Q000032:analysis*; D002645:Chickens; D002648:Child; D002675:Child, Preschool; D003208:Concanavalin A; D005136:Eye Proteins / Q000032:analysis*; D006801:Humans; D007158:Immunologic Techniques; D007223:Infant; D007231:Infant, Newborn; D007908:Lens, Crystalline / Q000032:analysis*; D008565:Membrane Proteins / Q000032:analysis; D008875:Middle Aged; D008970:Molecular Weight
D015820:Cadherins; D005136:Eye Proteins; D008565:Membrane Proteins; D003208:Concanavalin A