Question

Your major research project as a graduate student involves analyzing a collection of mutants isolated by your lab all of which have defects in some aspect of the secretory pathway.  For each of the mutants below, suggest where in the pathway the mutation might occur. If possible suggest a candidate gene that might be affected in that particular line.

1. Cells grow normally but produce no extracellular matrix
2. Cells grow normally and produce extracellular matrix but have reduced cells do not grow on the matrix
3. Cells do not secrete any protein but they do accumulate hundreds of vesicles
4. Cells do not secrete protein, of accumulate vesicles but have whorls of endoplasmic reticulum
5. Cells do not secrete protein and the ER looks fairly normal but there’s a curious lack of Rough ER

Answer 1

Cells grow normally and produce extracellular matrix but have reduced cells do not grow on matrix because the matrix forms a basal lamina which is important in controlling cell behavior.