Peptides derived from human galectin-3 N-terminal tail interact with its carbohydrate recognition domain in a phosphorylation-dependent manner

M. Alvaro Berbis, Sabine Andre, F. Javier Canada, Ruediger Pipkorn, Hans Ippel, Kevin H. Mayo, Dieter Kuebler, Hans-Joachim Gabius, Jesus Jimenez-Barbero*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Galectin-3 (Gal-3) is a multi-functional effector protein that functions in the cytoplasm and the nucleus, as well as extracellularly following non-classical secretion. Structurally, Gal-3 is unique among galectins with its carbohydrate recognition domain (CRD) attached to a rather long N-terminal tail composed mostly of collagen-like repeats (nine in the human protein) and terminating in a short non-collagenous terminal peptide sequence unique in this lectin family and not yet fully explored. Although several Ser and Tyr sites within the N-terminal tail can be phosphorylated, the physiological significance of this post-translational modification remains unclear. Here, we used a series of synthetic (phospho)peptides derived from the tail to assess phosphorylation-mediated interactions with N-15-labeled Gal-3 CRD. HSQC-derived chemical shift perturbations revealed selective interactions at the backface of the CRD that were attenuated by phosphorylation of Tyr 107 and Tyr 118, while phosphorylation of Ser 6 and Ser 12 was essential. Controls with sequence scrambling underscored inherent specificity. Our studies shed light on how phosphorylation of the N-terminal tail may impact on Gal-3 function and prompt further studies using phosphorylated full-length protein.
Original languageEnglish
Pages (from-to)126-131
JournalBiochemical and Biophysical Research Communications
Volume443
Issue number1
DOIs
Publication statusPublished - 3 Jan 2014

Keywords

  • Agglutinin
  • Collagen
  • Lectin
  • Phosphopeptide
  • Phosphorylation

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