Conventional and Unconventional Protein Secretion in Yeast and Animal Cells

Protein secretion mediated by the secretory transport pathway is a sophisticated and highly regulated cellular process in eukaryotic cells. In the conventional secretory transport pathway, newly synthesized proteins pass through several endomembrane compartments to reach their destinations. This transport occurs via small, membrane-enclosed vesicles. To ensure the fidelity of trafficking, eukaryotic cells employ elaborate molecular machinery to accurately sort newly synthesized proteins into specific transport vesicles and precisely deliver them to respective acceptor compartments. Leaderless cargo proteins, lacking a signal peptide, follow an unconventional secretory pathway. This review encompasses the molecular machinery regulating both conventional and unconventional protein secretion in yeast and animal cells.