Knudson W, Bartnik E, Knudson C B
Department of Biochemistry, Rush-Presbyterian-St. Luke's Medical Center, Chicago, IL 60612.
Proc Natl Acad Sci U S A. 1993 May 1;90(9):4003-7. doi: 10.1073/pnas.90.9.4003.
The capacity to assemble and retain a pericellular matrix is correlated with the expression of the cell surface binding sites specific for the extracellular matrix macromolecule hyaluronan. These binding proteins have been termed hyaluronan receptors. The lymphocyte-homing receptor CD44 may have identity with these hyaluronan receptors. To determine whether hyaluronan receptors function independently in this capacity for matrix assembly, mammalian cells were transfected with cDNA encoding the putative hyaluronan receptor CD44. After transfection with CD44 cDNA, COS cells gained the capacity to assemble hyaluronan-dependent pericellular matrices in the presence of exogenously added hyaluronan and proteoglycan. Thus, CD44 receptors do function as matrix-organizing, matrix-anchoring hyaluronan-binding proteins. In addition, the expression of CD44/hyaluronan receptors alone is sufficient to direct this matrix assembly. If matrix assembly is a function of cells in vivo that express hyaluronan receptors, this raises interesting possibilities for the role of the receptors in cell migration, when new extracellular matrix environments are encountered.
组装并维持细胞周围基质的能力与细胞表面针对细胞外基质大分子透明质酸的特异性结合位点的表达相关。这些结合蛋白被称为透明质酸受体。淋巴细胞归巢受体CD44可能与这些透明质酸受体相同。为了确定透明质酸受体是否独立发挥这种基质组装能力，用编码假定的透明质酸受体CD44的cDNA转染哺乳动物细胞。用CD44 cDNA转染后，COS细胞在存在外源添加的透明质酸和蛋白聚糖的情况下获得了组装透明质酸依赖性细胞周围基质的能力。因此，CD44受体确实作为组织基质、锚定基质的透明质酸结合蛋白发挥作用。此外，单独的CD44/透明质酸受体的表达足以指导这种基质组装。如果基质组装是体内表达透明质酸受体的细胞的功能，那么当遇到新的细胞外基质环境时，这就为受体在细胞迁移中的作用带来了有趣的可能性。
