Reduced temperature does not prevent transport of lysosomal integral membrane proteins from endoplasmic reticulum and through the Golgi system to lysosomes.

The effect of low temperature on the transport of three lysosomal integral membrane proteins (I, II and III) from endoplasmic reticulum to lysosomes has been studied in normal rat kidney cells. At 15 degrees C and 18 degrees C, though slowly, the proteins could leave the endoplasmic reticulum, move through the Golgi system from the cis to the trans side, and accumulate in lysosomes. Transport of these proteins at low temperature occurred slower than at 37 degrees C. Both at low temperature and 37 degrees C, the proteins were transported between the endoplasmic reticulum and Golgi (III greater than I and II) and from Golgi to lysosomes (II greater than III much greater than I) with different rates.