Which of the following is not a fate of a protein that is produced by the rough er?
it functions inside of an organelle that is a member of the endomembrane system.
it functions in the cytoskeleton as a tubulin component of microtubules.
is is secreted from the cell similar to how the protein called insulin is secreted from pancreatic cells.
it functions as a glycoprotein in the membranes of the golgi apparatus.