Localization of intracellular Ca2+ stores in HeLa cells during infection with Chlamydia trachomatis

Autor: Erik Kihlström, Karl-Heinz Krause, Robert A. Clark, Meytham Majeed, Olle Stendahl
Rok vydání: 1999
Předmět:
Calcium/ metabolism
Intracellular Fluid
Time Factors
Molecular Chaperones/immunology/metabolism
Fluorescent Antibody Technique
Receptors
Cytoplasmic and Nuclear
Chlamydia trachomatis
ddc:616.07
chemistry.chemical_compound
Adenosine Triphosphate
Antibody Specificity
Calcium Channels/immunology/metabolism
Chlamydia Infections/ metabolism/microbiology
Inositol 1
4
5-Trisphosphate Receptors
0303 health sciences
Emetine/pharmacology
Endocytosis
3. Good health
Cell biology
Sarcoplasmic Reticulum
Ribonucleoproteins
Receptors
Cytoplasmic and Nuclear/immunology/metabolism
Thapsigargin
Chloramphenicol/pharmacology
Endocytosis/physiology
Sarcoplasmic Reticulum/enzymology
Intracellular
Calcium-Transporting ATPases/antagonists & inhibitors/immunology/metabolism
SERCA
Endosome
Emetine
Chlamydiae
Chlamydia trachomatis/metabolism/pathogenicity
Calcium-Transporting ATPases
Biology
03 medical and health sciences
Extracellular
Humans
Thapsigargin/pharmacology
030304 developmental biology
030306 microbiology
Endoplasmic reticulum
Ribonucleoproteins/immunology/metabolism
Calcium-Binding Proteins
Cell Biology
Chlamydia Infections
biology.organism_classification
Calcium-Binding Proteins/immunology/metabolism
Chloramphenicol
chemistry
Cytoplasm
Hela Cells
Calcium
Calcium Channels
Adenosine Triphosphate/pharmacology
Intracellular Fluid/ metabolism
Calreticulin
HeLa Cells
Molecular Chaperones
Zdroj: Journal of Cell Science, Vol. 112, No 1 (1999) pp. 35-44
ISSN: 1477-9137
0021-9533
DOI: 10.1242/jcs.112.1.35
Popis: Chlamydia trachomatis elementary bodies (EBs) enter epithelial cells within membrane-bound endosomes that aggregate with each other in a calcium-regulated process, but avoid fusion with lysosomes. Annexin III but not I translocates to chlamydial aggregates and inclusions. In this study, we localize the intracellular Ca2+ stores during the course of infection by analyzing the distribution of three intracellular Ca2+ store proteins: calreticulin, type-1 inositol-1,4, 5-trisphosphate receptor (IP3-R), and Sarcoplasmic/Endoplasmic Reticulum Ca2+ ATPase type 2 (SERCA2) in HeLa cells infected with C. trachomatis serovar L2. In uninfected cells, immunofluorescence staining of the proteins showed a fine granular distributed pattern for all three proteins. After infection with C. trachomatis, calreticulin was found at the periphery of chlamydial aggregates and inclusions from 3 to 48 hours post-infection. In infected cells, SERCA2 was intimately associated with chlamydial inclusions after 3 and 24 hours, but not after 48 hours. Moreover, IP3-R was translocated to and colocalized with EB aggregates and chlamydial inclusions and had a distribution very similar to that of SERCA 2. After 24 hours incubation with chlamydiae, there was a local accumulation of [Ca2+]i (105+/-17 nM) in the proximity of chlamydial inclusions, compared to 50+/-13 nM in other parts of the cell cytoplasm. In the absence of extracellular Ca2+, this local accumulation of Ca2+ increased to 295+/-50 nM after adding 50 microM ATP, and to a similar extent after adding 100 nM thapsigargin (Tg). These data indicate that during infection of HeLa cells with chlamydiae, intracellular Ca2+ stores are redistributed, causing local accumulation of Ca2+ in the vicinity of chlamydial inclusions. These changes may trigger the association of certain proteins such as annexins with chlamydia-containing vesicles, and thereby regulation of membrane-membrane interaction during endosome aggregation and inclusion formation.
Databáze: OpenAIRE
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