1062-3604/05/3606- © 2005 Pleiades Publishing, Inc.
Russian Journal of Developmental Biology, Vol. 36, No. 6, 2005, pp. 377–385. Translated from Ontogenez, Vol. 36, No. 6, 2005, pp. 449–458.
Original Russian Text Copyright © 2005 by Prusov, Romanenko, Vanyushin.
A study of chromatin structure is of prime impor-
tance for deciphering the molecular mechanisms of
realization of the genome information and control over
the functioning of individual genes at different stages of
development. A special attention is paid to the interac-
tion of chromatin with the interphase nucleus skeletal
structure, nuclear envelope (NE). It has been proposed
that bases (SAR-sequences) of large structural and
functional domains (loops) are located on the strongest
NE element, lamina (Lewis
, 1984). Since the reg-
ulatory role in functioning of the loop is assigned to the
loop bases, changes in the structure and function of the
NE-bound chromatin regions can reﬂect changes in the
cell functional state.
Chromatin directly bound to the rat liver NE has
special features (Fais
, 1982; Prusov
low histone H1 content, presence of minor speciﬁc acid
soluble proteins, and weak DNA methylation. A part of
DNA of the peripheral chromatin is resistant to
nucleases and appears to be protected by proteins, On
the other hand, single stranded regions were found in
DNA from NE (Mizuno
, 1971), which is charac-
teristic of active genes; some constantly expressing
genes are located in the nucleus periphery at NE
, 2002). A lowered DNA methylation,
low histone H1 content, presence of speciﬁc proteins,
and other features suggest that this region of chromatin
can be related to the chromatin functioning and, in all
likelihood, to the regulation of its activity.
The regulatory chromatin region at the base of the
large loop domain can speciﬁcally participate in the
regulation of transcription and, possibly, replication.
Since this region is usually referred to heterochromatin,
it is mostly in the state of rest but, on the other hand, it
can react to global, including, age-related, changes in
the cell life. Chromatin is constantly on move in the
interphase nucleus; it can be temporarily detached and
then again attached to NE (Belmont, 2003) and, thus,
have different compositions at different times. The
structure and functioning of chromatin can also specif-
ically respond to various agents.
In this work, we studied age-related changes and
changes induced by the antioxidant ionol in the NE-
bound and not bound rat chromatin.
Changes in Composition of Acid Soluble Proteins and DNA
in Chromatin of Rat Liver and Brain Bound and Not Bound
to Nuclear Envelope as a Function of Age
and under the Influence of Antioxidant Ionol
A. N. Prusov, E. B. Romanenko, and B. F. Vanyushin
Belozersky Research Institute of Physicochemical Biology, Moscow State University, Vorob’evy gory, Moscow, 119992 Russia
Received March 31, 2005; in ﬁnal form, June 23, 2005
—In two-day rat pups, the histone H1 content in the brain chromatin was higher than in the liver chro-
matin, as compared to histone of the nucleosome core. The H1 content in the brain chromatin decreased with
the age, while in the liver chromatin it increased. At the same time, in the adult brain chromatin bound to the
nuclear envelope, a high level of H1 characteristic of chromatin of the newborn rats was preserved, while in a
similar chromatin of the adult liver, the H1 content increased, but still remained less than in the chromatin not
bound to the nuclear envelope. In both organs, the composition and quantitation of H1 subfractions were dif-
ferent in chromatins bound and not bound to the nuclear envelope. The chromatin from the liver and brain
bound to the nuclear envelope differed also in the composition and quantitation of minor acid soluble proteins.
In the presence of the antioxidant ionol, the 5-methylcytosine content in DNA of chromatin of the rat liver
bound to the nuclear envelope increased while in the chromatin not bound to the nuclear envelope, it remained
unchanged. Thus the chromatins bound and not bound to the nuclear envelope differ in the composition and
mount of acid soluble proteins, including histone H1, the contents of these proteins in bound and not bound
chromatin are different and change with the age in different ways. The antioxidant ionol affects differently the
methylation of bound and not bound chromatin.
: chromatin, nuclear envelope, ontogenesis, histone H1, acid soluble proteins, 5-mehtylcytosine,