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Updated: Aug 14, 2026

Method to Visualize and Analyze Membrane Interacting Proteins by Transmission Electron Microscopy
Published on: March 5, 2017
Dependence of Ypt1 and Sec4 membrane attachment on Bet2
1Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510.
Abstract:
Many small GTP-binding proteins are synthesized as soluble proteins that are post-translationally modified as a prerequisite for membrane attachment. Ypt1 and Sec4 are homologous Raslike GTP-binding proteins that have been proposed to regulate the specificity of vesicular traffic at different stages of the secretory pathway by cycling on and off membranes. Here we show that BET2, initially identified as a gene required for transport from endoplasmic reticulum to Golgi apparatus in yeast, encodes a factor that is needed for the membrane attachment of Ypt1 and Sec4. DNA sequence analysis has revealed that Bet2 is homologous to Dpr1 (Ram1), an essential component of a protein prenyltransferase that modifies Ras, enabling it to attach to membranes. We propose that Bet2 modifies Ypt1 and Sec4 in an analogous manner.
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