What Happens If a Human Galectin Enters the Endoplasmic Reticulum?

Methods Mol Biol. 2022:2442:247-288. doi: 10.1007/978-1-0716-2055-7_15.

Abstract

Mammalian galectins have no signal peptide, and it is not known what would happen if a galectin is directed to take the classical export route. The corresponding engineering of galectin-specific cDNA will answer questions on the fate of a signal peptide-bearing protein variant after its entry into the endoplasmic reticulum (ER). Affinity chromatography and mass-spectrometric analysis of occupancy of potential N-glycosylation sites for the galectin, binding and functional assays with cells as well as subcellular fractionation by density gradient ultracentrifugation and immunocytochemical colocalization with ER/Golgi markers report on aspects of the consequences of letting a galectin enter new territory. Applying these methods will help to clarify why galectins are leaderless and thus produced by free ribosomes.

Keywords: Autophagy; Calnexin; N-glycosylation; Routing; Secretion.

MeSH terms

  • Animals
  • Endoplasmic Reticulum* / metabolism
  • Galectins* / metabolism
  • Glycosylation
  • Golgi Apparatus / metabolism
  • Humans
  • Mammals / metabolism
  • Protein Sorting Signals

Substances

  • Galectins
  • Protein Sorting Signals