Sarco/endoplasmic-reticulum calcium ATPase SERCA1 is maintained in the endoplasmic reticulum by a retrieval signal located between residues 1 and 211

Biochem J. 2003 May 1;371(Pt 3):775-82. doi: 10.1042/BJ20021477.

Abstract

The location of sarco/endoplasmic-reticulum calcium ATPase (SERCA) retention/retrieval motifs in the sequence of the SERCA1 has been investigated by examining the subcellular location in COS-7 cells of enhanced-green-fluorescent-protein-tagged calcium-pump chimaeras. These chimaeras have been constructed from the fast-twitch SERCA1 and the plasma-membrane calcium ATPase PMCA3. The N-terminal, central and C-terminal segments of these calcium pumps were exchanged between SERCA1 and PMCA3. The segments exchanged correspond to residues 1-211, 212-711 and 712-994 of SERCA1, and residues 1-264, 265-788 and 789-1159 of PMCA3 respectively. Only chimaeras containing the N-terminal segment of SERCA1 were located in the endoplasmic reticulum (ER), whereas chimaeras containing the N-terminal segment from PMCA3 were able to escape from the ER and enter the endomembrane pathway en route for the plasma membrane. Co-localization of SERCA1 in COS-7 cells with the ER/Golgi-intermediate compartment marker ERGIC53 indicates that SERCA1 is maintained in the ER by a process of retrieval. These results indicate that the N-terminal region of SERCA1, containing transmembrane helices M1 and M2, contains an ER-retrieval signal.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • COS Cells
  • Calcium-Transporting ATPases / chemistry
  • Calcium-Transporting ATPases / metabolism*
  • Cation Transport Proteins
  • Endoplasmic Reticulum / metabolism*
  • Plasma Membrane Calcium-Transporting ATPases
  • Protein Binding
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Signal Transduction*
  • Subcellular Fractions / metabolism

Substances

  • Cation Transport Proteins
  • Plasma Membrane Calcium-Transporting ATPases
  • Sarcoplasmic Reticulum Calcium-Transporting ATPases
  • Calcium-Transporting ATPases