Distinct roles for dystroglycan, beta1 integrin and perlecan in cell surface laminin organization.

TY - JOUR

T1 - Distinct roles for dystroglycan, beta1 integrin and perlecan in cell surface laminin organization.

AU - Henry, M D

AU - Satz, J S

AU - Brakebusch, C

AU - Costell, M

AU - Gustafsson, E

AU - Fässler, R

AU - Campbell, K P

N1 - Keywords: Animals; Antigens, CD29; Cell Line; Cell Membrane; Cytoskeletal Proteins; Dystroglycans; Heparan Sulfate Proteoglycans; Humans; Laminin; Membrane Glycoproteins; Mice

PY - 2001

Y1 - 2001

N2 - Dystroglycan (DG) is a cell surface receptor for several extracellular matrix (ECM) molecules including laminins, agrin and perlecan. Recent data indicate that DG function is required for the formation of basement membranes in early development and the organization of laminin on the cell surface. Here we show that DG-mediated laminin clustering on mouse embryonic stem (ES) cells is a dynamic process in which clusters are consolidated over time into increasingly more complex structures. Utilizing various null-mutant ES cell lines, we define roles for other molecules in this process. In beta1 integrin-deficient ES cells, laminin-1 binds to the cell surface, but fails to organize into more morphologically complex structures. This result indicates that beta1 integrin function is required after DG function in the cell surface-mediated laminin assembly process. In perlecan-deficient ES cells, the formation of complex laminin-1 structures is defective, implicating perlecan in the laminin matrix assembly process. Moreover, laminin and perlecan reciprocally modulate the organization of the other on the cell surface. Taken together, the data support a model whereby DG serves as a receptor essential for the initial binding of laminin on the cell surface, whereas beta1 integrins and perlecan are required for laminin matrix assembly processes after it binds to the cell.

AB - Dystroglycan (DG) is a cell surface receptor for several extracellular matrix (ECM) molecules including laminins, agrin and perlecan. Recent data indicate that DG function is required for the formation of basement membranes in early development and the organization of laminin on the cell surface. Here we show that DG-mediated laminin clustering on mouse embryonic stem (ES) cells is a dynamic process in which clusters are consolidated over time into increasingly more complex structures. Utilizing various null-mutant ES cell lines, we define roles for other molecules in this process. In beta1 integrin-deficient ES cells, laminin-1 binds to the cell surface, but fails to organize into more morphologically complex structures. This result indicates that beta1 integrin function is required after DG function in the cell surface-mediated laminin assembly process. In perlecan-deficient ES cells, the formation of complex laminin-1 structures is defective, implicating perlecan in the laminin matrix assembly process. Moreover, laminin and perlecan reciprocally modulate the organization of the other on the cell surface. Taken together, the data support a model whereby DG serves as a receptor essential for the initial binding of laminin on the cell surface, whereas beta1 integrins and perlecan are required for laminin matrix assembly processes after it binds to the cell.

M3 - Journal article

C2 - 11228157

SN - 0021-9533

VL - 114

SP - 1137

EP - 1144

JO - Journal of Cell Science

JF - Journal of Cell Science

IS - Pt 6

ER -