Related Experiment Video
Updated: May 5, 2026

Assay for Adhesion and Agar Invasion in S. cerevisiae
Published on: November 8, 2006
A ras-like protein is required for a post-Golgi event in yeast secretion
Abstract:
Secretion is blocked at the post-Golgi stage within 5 min of a shift of sec4-8 cells from 25 degrees C to 37 degrees C. Analysis of SEC4 predicts a protein product of 23.5 kd molecular weight that shares 32% homology with ras proteins and is essential for growth. The regions of best homology are those involved in the binding and hydrolysis of GTP. Duplication of SEC4 suppresses post-Golgi-blocked mutations in three sec genes. These mutations are lethal when combined with sec4-8 at 25 degrees C. Mutations that block elsewhere on the pathway are not suppressed by the SEC4 duplication and are not lethal when combined with sec4-8. We propose that the SEC4 product is a GTP-binding protein that plays an essential role in controlling a late stage of the secretory pathway.
More Related Videos
10:02Applications of pHluorin for Quantitative, Kinetic and High-throughput Analysis of Endocytosis in Budding Yeast
Published on: October 23, 2016
09:03A Simple Fluorescence-based Reporter Assay to Identify Cellular Components Required for Ricin Toxin A Chain RTA Trafficking in Yeast
Published on: December 15, 2017
Related Concept Videos
Overview of Secretory Vesicles
Various proteins regulate the aggregation of molecules inside the secretory vesicles. Chromogranins...
Coat Assembly and GTPases
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Rab Proteins
Rab proteins switch between a cytosolic, GDP-bound inactive state and a membrane-anchored, GTP-bound active state. By themselves, Rabs show slow rates of GDP/GTP exchange and GTP hydrolysis. Thus, Rab proteins are considered...
Directing Proteins to the Rough Endoplasmic Reticulum
Post-translational Translocation of Proteins to the RER
Targeting proteins to the ER
Hsp40 and Hsp70 chaperone molecules bind the translated proteins in the cytosol to prevent their folding. The chaperone binding helps to keep the signal...
Rab Cascades