dictyNews
Electronic Edition
Volume 36, number 1
Jan 7, 2010

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Abstracts
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Developmental Gene Regulation by an Ancient Intercellular Communication 
System in Social Amoebae 

Asma Asghar, Marco Groth, Oliver Siol, Friedemann Gaube, Christoph 
Enzensperger, Gernot Glöckner, Thomas Winckler  


Protist, in press

The social amoebae (Dictyostelia) use quorum sensing-like communication 
systems to coordinate the periodic transition from uni- to multicellularity. 
The monophyletic descent of the Dictyostelia provides a unique opportunity 
to study the origin and adaptive evolution of such intercellular communication 
systems. We determined that the ability of aggregation-competent cells to 
respond to the intercellular messenger glorin occurred in the most ancient 
taxa of the Dictyostelia. We show using Illumina sequencing technology that 
glorin mediates rapid changes in gene expression at the transition from 
vegetative growth to aggregation, apparently without pronounced cross-talk 
with the cyclic AMP-based communication system that coordinates post-
aggregation events in these species. We conclude that peptide-based 
communication is the most ancient form of intercellular signaling in the 
evolution of multicellularity in the social amoebae, but has been repeatedly 
replaced by other communication systems during the monophyletic evolution 
of the social amoebae. Glorin communication has parallels with quorum 
sensing in that the molecule diffuses into the field, stimulates gene 
expression in receptive cells and coordinates a population-wide response.   


Submitted by Thomas Winckler [[log in to unmask]]
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Derivatives of Dictyostelium differentiation-inducing factors promote 
mitogen-activated IL-2 production via AP-1 in Jurkat cells

Katsunori Takahashi 1, Masami Murakami 1, Haruhisa Kikuchi 2, 
Yoshiteru Oshima 2, Yuzuru Kubohara 3

1 Department of Clinical Laboratory, Gunma University School of Medicine, 
Maebashi 371-8511, Japan
2 Laboratory of Natural Product Chemistry, Tohoku University Graduate School 
of Pharmaceutical Sciences, Aoba-yama, Aoba-ku, Sendai 980-8578, Japan
3 Department of Molecular and Cellular Biology, Institute for Molecular and 
Cellular Regulation, Gunma University, Maebashi 371-8512, Japan


Life Sciences, in press.

Aims: Differentiation-inducing factors (DIFs) are chlorinated alkylphenones 
found in the cellular slime mold Dictyostelium discoideum. DIF derivatives 
exhibit antiproliferative activities and promote glucose consumption in 
mammalian cells in vitro. Here, we assessed the ability of DIFs to regulate 
the immune system in a mammalian cell-line and investigated their 
mechanisms of action. 

Main methods: We examined the effects of 30 DIF derivatives on concanavalin 
A–induced interleukin-2 (IL-2) production (CIIP) in Jurkat T-cells. We also 
examined the effects of these DIF derivatives on the activity of three transcription 
factors required for CIIP: namely, activator protein-1 (AP-1), nuclear factor of 
activated T-cells (NFAT), and nuclear factor kappa B (NFkB).

Key findings: A reporter gene assay suggested that 2 DIF derivatives, termed 
DIF-1(+1) and DIF-3(3M), significantly promoted CIIP in Jurkat cells, at least 
in part, by enhancing the activity of AP-1. These 2 DIF derivatives had no 
significant effect on concanavalin A–induced interferon-gamma production. 
Significance: The results suggest that DIF derivatives could be developed 
as novel drugs for the activation of IL-2 production and resultant stimulation 
of the immune system.


Submitted by: Yuzuru Kubohara [[log in to unmask]]
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[End dictyNews, volume 36, number 1]