Final answer:
The central belief of the Roman Catholic Church not shared by Protestant denominations is Transubstantiation.
Step-by-step explanation:
The central belief of the Roman Catholic Church not shared by Protestant denominations is Transubstantiation. Transubstantiation is the doctrine that teaches that during the Eucharist, the bread and wine actually become the body and blood of Jesus Christ. This belief is significant in Catholic theology and practice, but it is not held by most Protestant denominations.