Skip to main content
Biology LibreTexts

17.8: Synthesis of Integral Membrane Proteins

  • Page ID
    89014
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \) \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)\(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\) \(\newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\) \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\) \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\) \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\) \( \newcommand{\Span}{\mathrm{span}}\)\(\newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    Integral membrane proteins may span a membrane one or more times or may simply be anchored (embedded) in the membrane at one end (Figure 17.20, below).

    Screen Shot 2022-05-24 at 7.16.25 PM.png
    Figure 17.20: Integral membrane proteins that span the entire membrane have one or more very hydrophobic stop transfer signals, in addition to their signal sequence. Such membrane proteins cross the membranes one or more times during their synthesis.

    N-terminal signal sequences guide ribosomes translating integral membrane proteins to the RER. But before such a protein can pass completely into the RER cisternae, a stop-transfer sequence (a hydrophobic domain within the polypeptide chain) traps the protein in the fatty acid interior of the membrane. Multiple stop-transfer sequences account for transmembrane proteins that span a membrane more than once.

    308-2 Integral Proteins Have Stop-Transfer Sequences


    This page titled 17.8: Synthesis of Integral Membrane Proteins is shared under a not declared license and was authored, remixed, and/or curated by Gerald Bergtrom.

    • Was this article helpful?