Final answer:
Proteins without a sorting signal stay in the cytosol of a eukaryotic cell, not being part of the endomembrane system transport to organelles like the Golgi apparatus or ER.
Step-by-step explanation:
Proteins that lack a sorting signal remain as permanent residents of the cytosol of a eukaryotic cell. The endomembrane system processes and ships proteins specified by the nucleus to various destinations such as the Rough Endoplasmic Reticulum (ER), Golgi apparatus, and lysosomes.
However, proteins made in the cytoplasm without a specific sorting signal do not enter the endomembrane pathway and therefore remain in the cytosol.