Actin binding to galectin-13/placental protein-13 occurs independently of the galectin canonical ligand-binding site

Xumin Li, Yuan Yao, Tianhao Liu, Keqi Gu, Qiuyu Han, Wenlu Zhang, Gabriela Jaramillo Ayala, Yuhan Liu, Heya Na, Jinyi Yu, Fan Zhang, Kevin H. Mayo, Jiyong Su

Research output: Contribution to journalArticlepeer-review

4 Scopus citations


The gene for galectin-13 (Gal-13, placental protein 13) is only present in primates, and its low expression level in maternal serum may promote preeclampsia. In the present study, we used pull-down experiments and biolayer interferometry to assess the interaction between Gal-13 and actin. These studies uncovered that human Gal-13 (hGal-13) and Saimiri boliviensis boliviensis (sGal-13) strongly bind to α- and β-/γ-actin, with Ca2+ and adenosine triphosphate, significantly enhancing the interactions. This in turn suggests that h/sGal-13 may inhibit myosin-induced contraction when vascular smooth muscle cells undergo polarization. Here, we solved the crystal structure of sGal-13 bound to lactose and found that it exists as a monomer in contrast to hGal-13 which is a dimer. The distribution of sGal-13 in HeLa cells is similar to that of hGal-13, indicating that monomeric Gal-13 is the primary form in cells. Even though sGal-13 binds to actin, hGal-13 ligand-binding site mutants do not influence hGal-13/actin binding, whereas the monomeric mutant C136S/C138S binds to actin more strongly than the wild-type hGal-13. Overall, our study demonstrates that monomeric Gal-13 binds to actin, an interaction that is independent of the galectin canonical ligand-binding site.

Original languageEnglish (US)
Pages (from-to)1219-1229
Number of pages11
Issue number9
StatePublished - Sep 1 2021
Externally publishedYes

Bibliographical note

Publisher Copyright:
© 2021 The Author(s) 2021. Published by Oxford University Press. All rights reserved.


  • actin-binding protein
  • galectin-13 (placental protein 13)
  • preeclampsia
  • the ligand-binding site
  • α-actin

PubMed: MeSH publication types

  • Journal Article
  • Research Support, Non-U.S. Gov't


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