REVIEW: Apoptosis in Unicellular Organisms: Mechanisms and Evolution

A. V. Gordeeva^*, Y. A. Labas, and R. A. Zvyagilskaya

Bach Institute of Biochemistry, Russian Academy of Sciences, Leninsky pr. 33, Moscow 119071, Russia; fax: (7-095) 954-2732; E-mail: anna_gord@mail.ru

^* To whom correspondence should be addressed.

Received December 24, 2003; Revision received February 6, 2004

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Data about the programmed death (apoptosis) in unicellular organisms, from bacteria to ciliates, are discussed. Firstly apoptosis appeared in lower eukaryotes, but its mechanisms in these organisms are different from the classical apoptosis. During evolution, the apoptotic process has been improving gradually, with reactive oxygen species and Ca²⁺ playing an essential role in triggering apoptosis. All eukaryotic organisms have apoptosis inhibitors, which might be introduced by viruses. In the course of evolution, caspases and apoptosis-inducing factor appeared before other apoptotic proteins, with so-called death receptors being the last among them. The functional analogs of eukaryotic apoptotic proteins take parts in the programmed death of bacteria.

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KEY WORDS: apoptosis, bacteria, Ca²⁺, caspases, death receptors, evolution, eukaryotes, reactive oxygen species

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