Chlamydia trachomatis suppresses host cell store-operated Ca2+ entry and inhibits NFAT/calcineurin signaling

Sci Rep. 2022 Dec 10;12(1):21406. doi: 10.1038/s41598-022-25786-y.


The obligate intracellular bacterium, Chlamydia trachomatis, replicates within a parasitophorous vacuole termed an inclusion. During development, host proteins critical for regulating intracellular calcium (Ca2+) homeostasis interact with the inclusion membrane. The inclusion membrane protein, MrcA, interacts with the inositol-trisphosphate receptor (IP3R), an ER cationic channel that conducts Ca2+. Stromal interaction molecule 1 (STIM1), an ER transmembrane protein important for regulating store-operated Ca2+ entry (SOCE), localizes to the inclusion membrane via an uncharacterized interaction. We therefore examined Ca2+ mobilization in C. trachomatis infected cells. Utilizing a variety of Ca2+ indicators to assess changes in cytosolic Ca2+ concentration, we demonstrate that C. trachomatis impairs host cell SOCE. Ca2+ regulates many cellular signaling pathways. We find that the SOCE-dependent NFAT/calcineurin signaling pathway is impaired in C. trachomatis infected HeLa cells and likely has major implications on host cell physiology as it relates to C. trachomatis pathogenesis.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Calcium / metabolism
  • Calcium Signaling* / physiology
  • Chlamydia trachomatis* / metabolism
  • Endoplasmic Reticulum / metabolism
  • HeLa Cells
  • Humans
  • ORAI1 Protein / metabolism
  • Stromal Interaction Molecule 1 / metabolism


  • Stromal Interaction Molecule 1
  • Calcium
  • ORAI1 Protein