Bip internal ribosome entry site (IRES)

The BiP internal ribosome entry site (IRES) is an RNA element present in the 5' UTR of the mRNA of BiP protein and allows cap-independent translation. BiP protein expression has been found to be significantly enhanced by the heat shock response due to internal ribosome entry site (IRES)-dependent translation. It is thought that this translational mechanism is essential for the survival of cells under stress.