Commitment events in early G1 requirement for the synthesis of dolichol dependent glycoproteins.

Dolichol functions as a carrier of oligosaccharides to polypeptide chains in the biosynthesis of N-linked glycoproteins. It is here reported that a short (4 hours) transient exposure to tunicamycin, (a specific inhibitor of dolichol dependent glycosylation) causes a cell cycle delay in post-mitotic 3T3-cells. From kinetic point of view the delay following treatment by tunicamycin resembles the delay caused by short exposures to serum deprivation or treatment by cycloheximide, indicating that the expression of N-linked glycoproteins may be involved in the cell cycle regulation. Evidence is that the availability of dolichol may be a limiting factor in this process is also presented.