Protein Secretion and Vesicle Traffic : Part 3: Human Diseases of Vesicle Budding (32:28)

Human COPII genes are duplicated and some may have evolved specialized functions. Two rare human diseases affect the... » More

Human COPII genes are duplicated and some may have evolved specialized functions. Two rare human diseases affect the activity of one of two copies of Sar1 and the Sec23A subunit of the COPII coat. Anderson's disease results in the failure of enterocytes of the absorptive epithelium to secrete large lipoprotein particles called chylomicrons. Point mutations in one of two copies of Sar1 results in the accumulation of chylomicrons in the ER. CLSD, a rare craniofacial disorder likely due to the selective failure of secretion of certain connective tissue proteins such as collagen, is caused by a conservative amino acid substitution in Sec23A that blocks completion of COPII coat assembly. « Hide