If a protein is bonded to ubiquitin, this tells the cell that the protein should be __________.

HMGCoA reductase (3-hydroxy-3-methyl-glutaryl-CoA reductase) is the rate-limiting enzyme in cholesterol synthesis. Which of the following are true about the ubiquitination of this enzyme?

I. When cholesterol levels in the cell are high, the reductase binds to insulin-induced gene 1 proteins.

II. Binding to insulin induced gene 1 proteins leads to ubiquitination and proteasomal degradation of reductase.

III. Ubiquitination occurs through the binding of the C-terminal glycine of ubiquitin to the amino group of a lysine on the reductase.

IV. The enzyme tagged with ubiquitin is recognized by the proteasome where proteolysis occurs.