Monoubiquitination Is Sufficient To Signal Internalization of the Maltose Transporter in Saccharomyces cerevisiae

Monoubiquitination of the 12-transmembrane segment (12-TMS) Saccharomyces cerevisiae maltose transporter promoted the maximal internalization rate of this protein. This modification is similar to that of the 7-TMS α-factor receptor but different from that of the 12-TMS uracil and general amino acid permeases. This result shows that binding of ubiquitin-Lys63 chains is not required for maximal internalization of all 12-TMS-containing proteins.