ISSN 1062-3604, Russian Journal of Developmental Biology, 2007, Vol. 38, No. 5, pp. 265–271. © Pleiades Publishing, Inc., 2007.
Original Russian Text © N.P. Sharova, T.M. Astakhova, L.A. Bondareva, S.B. Dmitrieva, S.D. Stolyarov, 2007, published in Ontogenez, 2007, Vol. 38, No. 5, pp. 323–329.
AND THEIR ROLE IN IMMUNE RESPONSE
Mammalian cells contain multiple forms of protea-
somes, which differ in subunit composition, substrate
speciﬁcity, and functions. The entire diversity of these
forms can be reduced to the two main pools of protea-
somes: 26S and 20S (Fig. 1). The ﬁrst pool includes
26S proteasomes per se consisting of proteolytic
20S-”nucleus” and two regulatory 19S-subunits and
mixed proteasomes, in which one 19S-subunit is substi-
tuted by another regulator (PA28, PA200). The pool of
26S-proteasomes realizes ATP-dependent hydrolysis of
ubiquitinated proteins and regulates in this way multi-
ple cell processes, in which these processes are
involved (Rock and Goldberg, 1999; Abramova et al.,
2002). The pool of 20S-proteaseomes destroys the pro-
teins damaged by oxidation irrespective of ubiquitin
In turn, the pools of 26S- and 20S-proteasomes of
mammals can be divided in two groups by the set of
proteolytically active subunits: constitutive and
immune (Sharova, 2006). Immune proteasomes contain
catalytic subunits LMP7 (
i, and MECL1
i) induced by
-interferon instead of catalytic sub-
units X (
), Y (
), and Z (
) of constitutive protea-
somes. Constitutive subunits are substituted for the
immune subunits during assembly of new proteasomes.
Subunits LMP2 and MECL1 are incorporated jointly,
but independently from LMP7. Although incorporation
of subunit LMP7 in a newly formed proteasome is facil-
itated by the presence of LMP2 and MECL1, but it can
be realized in their absence (Groettrup et al., 1997;
Grifﬁn et al., 1998). Thus, three types of immune pro-
teasomes are formed: subtype containing all
feron-induced catalytic subunits, subtypes containing
subunits LMP2 and MECL1, and subtype possessing
subunits LMP7 only, which were found in some mam-
malian organs (Dahlmann et al., 2000, 2001; Astakhova
and Sharova, 2006).
Formation of Immune Proteasomes and Development
of Immune System in Ontogenesis of Mammals
N. P. Sharova*, T. M. Astakhova*, L. A. Bondareva**, S. B. Dmitrieva*, and S. D. Stolyarov*
*Kol’tsov Institute of Developmental Biology, Russian Academy of Sciences,
u. Vavilova 26, Moscow, 119334 Russia
**Institute of Biology, Karelian Research Center of the Russian Academy of Sciences,
Pushkinskaya ul., 11, Petrozavodsk, 185610 Russia
Received May 22, 2006; in ﬁnal form, July 4, 2006
—Current concepts of the structure of immune proteasomes and their role in immune response have
been considered. The main attention has been paid to the formation of immune proteasomes in secondary lym-
phoid and nonlymphoid organs during ontogenesis of mammals. The causes of ineffective formation of immune
system in early postnatal development have been discussed.
: immune proteasomes, T-cellular immunity, development of immune system.
Schematic diagram of 26S- and 20S-proteaseomes.