dictyNews
Electronic Edition
Volume 48, number 4
February 25, 2022
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
=========
Dictyostelium spastin is involved in nuclear envelope dynamics
during semi-closed mitosis
Ulrike Schweigel1, Petros Batsios1, Annette Müller-Taubenberger2,
Ralph Gräf1* and Marianne Grafe1*
1University of Potsdam, Institute for Biochemistry and Biology,
Dept. of Cell Biology, Karl-Liebknecht-Str. 24-25, 14476
Potsdam-Golm, Germany
2LMU Munich, Biomedical Center, Department of Cell Biology,
Großhaderner Straße 9, 82152 Planegg-Martinsried, Germany
Nucleus, in press
Dictyostelium amoebae perform a semi-closed mitosis, in which
the nuclear envelope is fenestrated at the insertion sites of
the mitotic centrosomes and around the central spindle during
karyokinesis. During late telophase the centrosome relocates
to the cytoplasmic side of the nucleus and the central spindle
disassembles to allow closure of the nuclear fenestrae. In a
search for candidate proteins involved in this process we
focused on the AAA-ATPase spastin. Our data indicate that
Dictyostelium spastin (DdSpastin) is a microtubule-binding and
severing type I membrane protein. We have studied its mitotic
localization in a DdSpastin-NEON knock-in strain. While the
fusion protein showed no specific localization during interphase,
it started to accumulate at spindle poles in early telophase
followed by appearance at the central spindle in late telophase,
where it formed discrete spots close to the nuclear envelope
fenestrae. This suggests a requirement of DdSpastin for the
removal of microtubules that could hinder closure of the
fenestrae both at the poles and at the spindle. Furthermore,
DdSpastin interacted with the HeH/LEM-family protein Src1 in
BioID analyses and co-localized with Src1 at the poles and the
spindle. BioID also revealed a novel interaction with Sun1,
which co-localized with DdSpastin at the poles. Furthermore,
we could show an additional co-localization with the ESCRT
component CHMP7 and the IST1-domain containing protein
filactin suggesting that the principal pathway of nuclear envelope
remodeling in late mitosis is conserved between human cells
and Dictyostelium amoebae.
Submitted by Ralph Gräf [[log in to unmask]]
=======================================================
[End dictyNews, volume 48, number 4]
|
