A NEURONAL CELL-LINE (PC12) EXPRESSES 2 BETA-1-CLASS INTEGRINS ALPHA-1-BETA-1 AND ALPHA-3-BETA-1 THAT RECOGNIZE DIFFERENT NEURITE OUTGROWTH-PROMOTING DOMAINS IN LAMININ

Integrins mediate neuronal process outgrowth on components of the ECM. Integrin a subunit-specific antibodies have been used to examine the roles of individual β1 integrins in attachment and neurite outgrowth by the neuronal cell line, PC12, in response to laminin and collagen. α1β1, and α3β1 were identified as the major β1 integrins expressed by PC12 cells. In functional assays, both α1β1, and α3β1 mediated PC12 cell interactions with laminin, whereas α1β1 alone mediated responses to collagen types I and IV. α1β1, and α3β1 were shown to recognize two different neurite-promoting sites in laminin: α1β1 interacted with the cross-region of laminin present in proteolytic fragments E1-4 and E1; α3β1 recognized a site in the long arm contained in laminin fragment E8. Thus, PC12 cells express two β1 integrins, which together function in attachment and neurite outgrowth on laminin and collagen. These integrins are candidates for mediating neurite outgrowth of sympathetic and other neurons in response to these ECM components. © 1990.