SAWYER, Sara J.; UHL, Nicholas; Southern Illinois Univeristy; Southern Illinois University: Identification of an integrin and integrin associated proteins in the sea anemone, Aiptasia pulchella, and the hydroid, Hydra littoralis

Integrins are an ancient group of animal adhesion receptors that attach cells to the extracellular matrix. Integrins are composed of heterodimeric transmembrane proteins consisting of one &alpha and one &beta subunit. On the cytoplasmic side, integrins link to a variety of different proteins that either function in signaling or connect the integrin to the cytoskeleton. Integrin sequences have been identified in Cnidarians; however, the function of integrins in these animals has not been investigated. In this study we have identified an approximately 120 kDa protein from tissue extracts from both Hydra littoralis and the sea anemone, Aiptasia pulchella that reacts with an anti- &beta 1 integrin antibody. In addition, we have identified by immunoprecipitation using an anti-focal adhesion kinase antibody an approximately 125 kDa a protein in tissue extract from both H. littoralis and A. pulchella. We have also identified an approximately 60 kDa protein by immunoprecipitation using an anti-paxillin antibody in tissue extracts from H. littoralis. Thus an integrin and integrin adhesion complex proteins involved in signaling (focal adhesion kinase) and in connecting the integrin to the actin cytoskeleton (paxillin) have been identified from two different species of Cnidarians. Future studies will investigate the tissue localization of these proteins as well as study functional regulation of the different interactions between these proteins.