pHuji, a pH-sensitive red fluorescent protein for imaging of exo- and endocytosis

J Cell Biol. 2014 Nov 10;207(3):419-32. doi: 10.1083/jcb.201404107.

Abstract

Fluorescent proteins with pH-sensitive fluorescence are valuable tools for the imaging of exocytosis and endocytosis. The Aequorea green fluorescent protein mutant superecliptic pHluorin (SEP) is particularly well suited to these applications. Here we describe pHuji, a red fluorescent protein with a pH sensitivity that approaches that of SEP, making it amenable for detection of single exocytosis and endocytosis events. To demonstrate the utility of the pHuji plus SEP pair, we perform simultaneous two-color imaging of clathrin-mediated internalization of both the transferrin receptor and the β2 adrenergic receptor. These experiments reveal that the two receptors are differentially sorted at the time of endocytic vesicle formation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Clathrin-Coated Vesicles / metabolism
  • Directed Molecular Evolution
  • Endocytosis*
  • Exocytosis*
  • Hydrogen-Ion Concentration
  • Luminescent Proteins / chemistry
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism*
  • Mice
  • Microscopy, Fluorescence
  • NIH 3T3 Cells
  • Protein Transport

Substances

  • Luminescent Proteins
  • red fluorescent protein