title: Determining protein transport to the plasma membrane.
abstract: Many integral membrane proteins synthesized in the endoplasmic reticulum ultimately arrive at the cell surface to contact the cell environment. During transit through the Golgi and trans-Golgi network, proteins acquire post-translational modifications that can be used to track the appearance of such modified proteins at the cell surface. Cellular proteins can be treated with enzymes-e.g., sialidase or protease-or antibodies, or biotinylated to identify molecules that have reached the cell surface. Some proteins first enter the endocytic pathway before appearing at the cell surface; this is detected by treating the cells at 4 degrees and 37 degrees C. Analysis of the number of sialic acids on proteins of cells treated at 4 degrees C identifies proteins resident at the cell surface, while cells treated at 37 degrees C internalize the sialidase, which can then act with proteins in the endocytic compartments.
authors.affiliation: The Netherlands Cancer Institute, Amsterdam, The Netherlands.
authors.forename: J
authors.initials: J
authors.lastname: Neefjes
mesh_terms: D000818:Animals; D002462:Cell Membrane / Q000502:physiology*; D004721:Endoplasmic Reticulum / Q000502:physiology; D006056:Golgi Apparatus / Q000502:physiology; D006801:Humans; D011499:Protein Processing, Post-Translational / Q000502:physiology; D021381:Protein Transport / Q000502:physiology*