Biochemistry (Moscow)

, Volume 77, Issue 11, pp 1277–1284

Cellular acidosis inhibits assembly, disassembly, and motility of stress granules

  • E. M. Chudinova
  • E. S. Nadezhdina
  • P. A. Ivanov

DOI: 10.1134/S0006297912110065

Cite this article as:
Chudinova, E.M., Nadezhdina, E.S. & Ivanov, P.A. Biochemistry Moscow (2012) 77: 1277. doi:10.1134/S0006297912110065


Stress granules (SGs) are large ribonucleoprotein (RNP)-containing particles that form in cytoplasm in response to a variety of acute changes in the cellular environment. One of the general parameters of the cell environment is pH. In some diseases, as well as in muscle fatigue, tissue acidosis occurs, leading to decrease in intracellular pH. Here we studied whether decrease in pH causes the formation of SGs in cultured animal cells, whether it affects the formation of the SGs under the action of arsenite and, if such effects occur, what are the mechanisms of the influence of acidosis. Acidosis was simulated by decreasing the pH of the culture medium, which acidified the cytoplasm. We found that medium acidification to pH 6.0 in itself did not cause formation of SGs in cells. Moreover, acidification prevented the formation of SGs under treatment with sodium arsenite or sodium arsenite together with the proteasome inhibitor MG132, and it inhibited the dissociation of preformed SGs under the influence of cycloheximide. We established that pH decrease did not affect the phosphorylation of eIF2α that occurs under the action of sodium arsenite, and even caused such phosphorylation by itself. We also found that the velocity of SG motion in cytoplasm at acidic pH was very low, and the mobile fraction of SG-incorporated PABP protein revealed by FRAP was decreased. We suppose that acidic pH impairs biochemical processes favoring assembly of RNPs in stress conditions and RNP dissociation on the termination of stress. Thus, in acidosis the reaction of the cellular translation apparatus to stress is modified.

Key words

RNP cytoplasm pH sodium arsenite FRAP microtubule 



fluorescence recovery after photobleaching




stress granule

Copyright information

© Pleiades Publishing, Ltd. 2012

Authors and Affiliations

  • E. M. Chudinova
    • 1
  • E. S. Nadezhdina
    • 1
    • 2
  • P. A. Ivanov
    • 2
    • 3
  1. 1.Institute of Protein ResearchRussian Academy of SciencesPushchino, Moscow RegionRussia
  2. 2.Belozersky Institute of Physico-Chemical BiologyLomonosov Moscow State UniversityMoscowRussia
  3. 3.Biological FacultyLomonosov Moscow State UniversityMoscowRussia

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