Answer:
The second statement is incorrect.
Step-by-step explanation:
The proteins generated in the rough endoplasmic reticulum can be sorted to the cell membrane, Golgi apparatus, exterior to the cell, and lysosome.
As a component of microtubules tubulin is found in cytoplasm and these proteins of cytoplasm originate due to the translation process undergone by the cytoplasmic ribosomes, not by the ribosomes present on the rough endoplasmic reticulum. Thus, these proteins are not a component of endomembrane system.