title: Polyphyly of nuclear lamin genes indicates an early eukaryotic origin of the metazoan-type intermediate filament proteins.
abstract: The nuclear lamina is a protein meshwork associated with the inner side of the nuclear envelope contributing structural, signalling and regulatory functions. Here, I report on the evolution of an important component of the lamina, the lamin intermediate filament proteins, across the eukaryotic tree of life. The lamins show a variety of protein domain and sequence motif architectures beyond the classical α-helical rod, nuclear localisation signal, immunoglobulin domain and CaaX motif organisation, suggesting extension and adaptation of functions in many species. I identified lamin genes not only in metazoa and Amoebozoa as previously described, but also in other opisthokonts including Ichthyosporea and choanoflagellates, in oomycetes, a sub-family of Stramenopiles, and in Rhizaria, implying that they must have been present very early in eukaryotic evolution if not even the last common ancestor of all extant eukaryotes. These data considerably extend the current perception of lamin evolution and have important implications with regard to the evolution of the nuclear envelope.
authors.affiliation: Group Systems Biology of Motor Proteins, Department of NMR-based Structural Biology, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Kollmar
mesh_terms: D000818:Animals; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D056890:Eukaryota / Q000235:genetics*; D019143:Evolution, Molecular; D020869:Gene Expression Profiling; D007381:Intermediate Filament Proteins / Q000737:chemistry / Q000145:classification / Q000235:genetics*; D034882:Lamins / Q000737:chemistry / Q000235:genetics*; D054730:Protein Interaction Domains and Motifs
chemical_list: D007381:Intermediate Filament Proteins; D034882:Lamins