dictyNews
Electronic Edition
Volume 41, number 3
January 30, 2015
Please submit abstracts of your papers as soon as they have been
accepted for publication by sending them to [log in to unmask]
or by using the form at
http://dictybase.org/db/cgi-bin/dictyBase/abstract_submit.
Back issues of dictyNews, the Dicty Reference database and other
useful information is available at dictyBase - http://dictybase.org.
Follow dictyBase on twitter:
http://twitter.com/dictybase
=========
Abstracts
=========
Comparative genome and transcriptome analyses of the social amoeba
Acytostelium subglobosum that accomplishes multicellular development
without germ-soma differentiation.
Hideko Urushihara, Hidekazu Kuwayama, Kensuke Fukuhara, Takehiko
Itoh, Hiroshi Kagoshima, Tadasu Shin-I, Atsushi Toyoda, Kazuyo
Ohishi, Tateaki Taniguchi, Hideki Noguchi, Yoko Kuroki, Takashi
Hata, Kyoko Uchi, Kurato Mohri, Jason S. King, Robert H. Insall,
Yuji Kohara, Asao Fujiyama.
BMC Genomics, in press.
Background: Social amoebae are lower eukaryotes that inhabit the
soil. They are characterized by the construction of a starvation-
induced multicellular fruiting body with a spore ball and
supportive stalk. In most species, the stalk is filled with motile
stalk cells, as represented by the model organism Dictyostelium
discoideum, whose developmental mechanisms have been well
characterized. However, in the genus Acytostelium, the stalk is
acellular and all aggregated cells become spores. Phylogenetic
analyses have shown that it is not an ancestral genus but has
lost the ability to undergo cell differentiation.
Results: We performed genome and transcriptome analyses of
Acytostelium subglobosum and compared our findings to other
available dictyostelid genome data. Although A. subglobosum
adopts a qualitatively different developmental program from other
dictyostelids, its gene repertoire was largely conserved. Yet,
families of polyketide synthase and extracellular matrix proteins
have not expanded and a serine protease and ABC transporter B
family gene, tagA, and a few other developmental genes are missing
in the A. subglobosum lineage. Temporal gene expression patterns
are astonishingly dissimilar from those of D. discoideum, and only
a limited fraction of the ortholog pairs shared the same expression
patterns, so that some signaling cascades for development seem to
be disabled in A. subglobosum.
Conclusions: The absence of the ability to undergo cell
differentiation in Acytostelium is accompanied by a small change
in coding potential and extensive alterations in gene expression
patterns.
Submitted by Hideko Urushihara [[log in to unmask]]
----------------------------------------------------------------------
A Long-range Foresight for the Medical Application of Apoptosis
Specifically Induced by Dd-MRP4, Dictyostelium Mitochondrial
Ribosomal Protein S4, to Cancer Therapy
Yasuo Maeda
Department of Developmental Biology and Neurosciences ,
Graduate School of Life Sciences, Tohoku University (Emeritus),
Aoba, Sendai 980-8578, Japan; E-mail: [log in to unmask]
Biomolecules, in press
Apoptosis (programmed cell death) is regarded as ultimate
differentiation of the cell. We have recently demonstrated that
a targeted delivery of Dd-MRP4 (Dictyostelium mitochondrial
ribosomal protein S4) suppresses specifically the proliferation
of the human cancer cells, by inducing their apoptotic cell
death [1]. This amazing fact was discovered, simply based on the
finding that Dd-MRP4 expression is absolutely required for
transition of Dictyostelium cells from growth to differentiation
[2,3]. Dd-MRP4 protein has quite unique structural characters, in
that it is highly basic (pI: about 11.5) and interestingly has
several nuclear-localization signals within the molecule. In this
review, we introduce briefly the efficacy of several apoptosis-
inducing substances reported thus far for cancer therapy, and
speculate the possible mechanisms, by which apoptosis is
specifically induced by Dd-MRP4, on the basis of its structural
uniqueness. We also discuss about several issues to be solved for
the medical application of ectopically expressed Dd-MRP4 in human
cancer cells.
Keywords: apoptosis; cell differentiation; cancer therapy; Dd-MRP4
(Dictyostelium mitochondrial ribosomal protein S4); microRNA
(miRNA); mitochondria; Dictyostelim discoideum; human cancer
cells
(References)
1. Chida, J.; Araki, H.; Maeda Y. Specific growth suppression
of human cancer cells by targeted delivery of Dictyostelium
mitochondrial ribosomal protein S4. Cancer Cell International
2014, 14:56.
2. Chida, J.; Amagai, A.; Tanaka, M.; Maeda Y. Establishment
of a new method for precisely determining the functions of
individual mitochondrial genes using Dictyostelium cells.
BMC Genet. 2008, 9:.doi:10.1186/1471-2156-9-25.
3. Maeda, Y.; Chida, J. Control of cell differentiation by
mitochondria, typically evidenced in Dictyostelium development.
Biomolecules 2013, 3, 943-966; doi:10.3390/biom3040943.
Submitted by Yasuo Maeda [[log in to unmask]]
==============================================================
[End dictyNews, volume 41, number 3]
|
