title: A lamin in lower eukaryotes?
abstract: Lamins are the major components of the nuclear lamina and serve not only as a mechanical support, but are also involved in chromatin organization, epigenetic regulation, transcription and mitotic events. Despite these universal tasks, lamins have so far been found only in metazoans. Yet, recently we have identified Dictyostelium NE81 as the first lamin-like protein in a lower eukaryote. Based on the current knowledge, we draw a model for nuclear envelope organization in Dictyostelium in this Extra View and we review the experimental data that justified this classification. Furthermore we provide unpublished data underscoring the requirement of posttranslational CaaX-box processing for proper protein localization at the nuclear envelope. Sequence comparison of NE81 sequences from four Dictyostelia with bona fide lamins illustrates the evolutional relationship between these proteins. Under certain conditions these usually unicellular social amoebae congregate to form a multicellular body. We propose that the evolution of the lamin-like NE81 went along with the invention of multicellularity.
authors.affiliation: Department of Cell Biology, Institute for Biochemistry and Biology, University of Potsdam, Potsdam-Golm, Germany.
authors.forename: Petros
authors.initials: P
authors.lastname: Batsios
authors.forename: Tatjana
authors.initials: T
authors.lastname: Peter
authors.forename: Otto
authors.initials: O
authors.lastname: Baumann
authors.forename: Reimer
authors.initials: R
authors.lastname: Stick
authors.forename: Irene
authors.initials: I
authors.lastname: Meyer
authors.forename: Ralph
authors.initials: R
authors.lastname: Gräf
mesh_terms: D019883:Alkyl and Aryl Transferases / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002467:Cell Nucleus / Q000378:metabolism; D018385:Centrosome / Q000378:metabolism; D004023:Dictyostelium / Q000378:metabolism; D034882:Lamins / Q000737:chemistry / Q000378:metabolism*; D009685:Nuclear Envelope / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D034882:Lamins; D015800:Protozoan Proteins; D019883:Alkyl and Aryl Transferases; C064911:p21(ras) farnesyl-protein transferase