TY  - JOUR
A1  - Meyer, Irene
A1  - Peter, Tatjana
A1  - Batsios, Petros
A1  - Kuhnert, Oliver
A1  - Krueger-Genge, Anne
A1  - Camurca, Carl
A1  - Gräf, Ralph
T1  - CP39, CP75 and CP91 are major structural components of the Dictyostelium
JF  - European journal of cell biology
N2  - The acentriolar Dictyostelium centrosome is a nucleus-associated body consisting of a core structure with three plaque-like layers, which are surrounded by a microtubule-nucleating corona. The core duplicates once per cell cycle at the G2/M transition, whereby its central layer disappears and the two outer layers form the mitotic spindle poles. Through proteomic analysis of isolated centrosomes, we have identified CP39 and CP75, two essential components of the core structure. Both proteins can be assigned to the central core layer as their centrosomal presence is correlated to the disappearance and reappearance of the central core layer in the course of centrosome duplication. Both proteins contain domains with centrosome-binding activity in their N- and C-terminal halves, whereby the respective N-terminal half is required for cell cycle-dependent regulation. CP39 is capable of self-interaction and GFP-CP39 overexpression elicited supernumerary microtubule-organizing centers and pre-centrosomal cytosolic clusters. Underexpression stopped cell growth and reversed the MTOC amplification phenotype. In contrast, in case of CP75 underexpression of the protein by RNAi treatment elicited supernumerary MTOCs. In addition, CP75RNAi affects correct chromosome segregation and causes co-depletion of CP39 and CP91, another central core layer component. CP39 and CP75 interact with each other directly in a yeast two-hybrid assay. Furthermore, CP39, CP75 and CP91 mutually interact in a proximity-dependent biotin identification (BioID) assay. Our data indicate that these three proteins are all required for proper centrosome biogenesis and make up the major structural components of core structure's central layer.
KW  - Dictyostelium
KW  - Mitosis
KW  - Microtubules
KW  - Centrosome
KW  - Nucleus
Y1  - 2017
U6  - https://doi.org/10.1016/j.eicb.2017.01.004
SN  - 0171-9335
SN  - 1618-1298
VL  - 96
SP  - 119
EP  - 130
PB  - Elsevier
CY  - Jena
ER  - 
TY  - JOUR
A1  - Gräf, Ralph
A1  - Batsios, Petros
A1  - Meyer, Irene
T1  - Evolution of centrosomes and the nuclear lamina: Amoebozoan assets
JF  - European journal of cell biology
N2  - The current eukaryotic tree of life groups most eukaryotes into one of five supergroups, the Opisthokonta, Amoebozoa, Archaeplastida, Excavata and SAR (Stramenopile, Alveolata, Rhizaria). Molecular and comparative morphological analyses revealed that the last eukaryotic common ancestor (LECA) already contained a rather sophisticated equipment of organelles including a mitochondrion, an endomembrane system, a nucleus with a lamina, a microtubule-organizing center (MTOC), and a flagellar apparatus. Recent studies of MTOCs, basal bodies/centrioles, and nuclear envelope organization of organisms in different supergroups have clarified our picture of how the nucleus and MTOCs co-evolved from LECA to extant eukaryotes. In this review we summarize these findings with special emphasis on valuable contributions of research on a lamin-like protein, nuclear envelope proteins, and the MTOC in the amoebozoan model organism Dictyostelium discoideum. (C) 2015 Elsevier GmbH. All rights reserved.
KW  - LINC complex
KW  - Sun1
KW  - Nuclear lamina
KW  - Lamin
KW  - Nuclear envelope
KW  - Centrosome
KW  - Basal body
KW  - Centriole
KW  - LEM-domain
Y1  - 2015
U6  - https://doi.org/10.1016/j.ejcb.2015.04.004
SN  - 0171-9335
SN  - 1618-1298
VL  - 94
IS  - 6
SP  - 249
EP  - 256
PB  - Elsevier
CY  - Jena
ER  -