Complex sentence: Another interesting role played by Originally, PDZ domains were believed to exclusively bind receptor proteins to cytoskeletal components, however new research shows that PDZ domains are also involved in the regulation of different cellular pathways.
Split into simpler sentences: Another interesting role played by Originally, the main function of PDZ domains was thought to be the anchoring of receptor proteins to cytoskeletal components. New research shows that PDZ domains are also involved in the regulation of different cellular pathways.