Copy Link
Add to Bookmark
Report
dictyNews Volume 40 Number 03
dictyNews
Electronic Edition
Volume 40, number 3
January 24, 2014
Please submit abstracts of your papers as soon as they have been
accepted for publication by sending them to dicty@northwestern.edu
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
=========
Evolution of the nucleus
Damien P. Devos, Ralph Graef and Mark C. Field
Current Opinion in Cell Biology, in press
The nucleus represents a major evolutionary transition. The consequence
of separating translation from transcription allowed many new functions to
arise, which likely contributed to the remarkable success of eukaryotic cells.
Here we will consider what has recently emerged on the evolutionary
histories of several key aspects of nuclear biology; the nuclear pore
complex, the lamina, centrosomes and evidence for prokaryotic origins
of important players.
Submitted by Ralph Graef [graef@uni-potsdam.de]
---------------------------------------------------------------------------
An ancestral non-proteolytic role for presenilin proteins in multicellular
development of the social amoeba Dictyostelium discoideum
Marthe H.R. Ludtmann*, Grant P. Otto*, Christina Schilde, Zhi-Hui Chen,
Claire Y. Allan, Selina Brace, Philip W. Beesley, Alan R. Kimmel,
Paul Fisher, Richard Killick, Robin S.B. Williams
Journal of Cell Science, in press
Mutations in two presenilin genes cause familial Alzheimer’s disease.
Presenilins have both proteolysis-dependent functions as components of
the gamma-secretase complex and proteolysis independent functions in
signalling. In this study we investigate a conserved function of human
presenilins in the development of the simple model Dictyostelium
discoideum. We show that the block in Dictyostelium development caused
by ablation of both Dictyostelium presenilins is rescued by expression of
human presenilin 1, restoring terminal differentiation of multiple cell types.
This developmental role is independent of proteolytic activity, since
mutation of both catalytic aspartates does not affect presenilin ability to
rescue development, and ablation of nicastrin, a gamma-secretase
component critical for proteolytic activity, does not block development.
The role of presenilins during Dictyostelium development is therefore
independent of their proteolytic activity. However, presenilin loss in
Dictyostelium results in elevated cyclic AMP (cAMP) levels and enhanced
stimulation-induced calcium release, suggesting that presenilins regulate
these intracellular signalling pathways. Our data suggest that presenilin
proteins perform an ancient non-proteolytic role in regulating intracellular
signalling and development, and that Dictyostelium is a useful model for
analysing human presenilin function.
Submitted by Robin Williams [robin.williams@rhul.ac.uk]
==============================================================
[End dictyNews, volume 40, number 3]
