title: Nucleostemin: a latecomer with new tricks.
abstract: Nucleostemin was first identified in neural stem cells and has become a focus of research in cell cycle control, tumorigenesis and cellular senescence. As the biology of nucleostemin begins to be unveiled in multiple species, an ensuing task is to resolve the apparent differences between the functions of mammalian and invertebrate nucleostemin and its homologues, an issue of pressing interest given the role of nucleostemin in stem cell self-renewal and tissue regeneration. A genome-wide search reveals that nucleostemin and its closest homologue, GNL3L, only emerge as separate genes in vertebrates and possess conserved protein sequences as evolution proceeded to the Mammalia. The invertebrate orthologue of nucleostemin and GNL3L resembles GNL3L more than it does nucleostemin in function, raising the idea that nucleostemin acquires new properties while GNL3L inherits an evolutionarily fixed role, and that the birth of nucleostemin may signify the appearance of new functional features in the vertebrate lineage.
authors.affiliation: Center for Cancer and Stem Cell Biology, Alkek Institute of Biosciences and Technology, Texas A&M University System Health Science Center, 2121 W. Holcombe Blvd, Houston, TX 77030, USA. rtsai@ibt.tamhsc.edu
authors.forename: Robert Y L
authors.initials: RY
authors.lastname: Tsai
authors.forename: Lingjun
authors.initials: L
authors.lastname: Meng
mesh_terms: D000818:Animals; D006801:Humans; D009687:Nuclear Proteins / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D021381:Protein Transport; D012038:Regeneration; D014714:Vertebrates / Q000378:metabolism
chemical_list: D009687:Nuclear Proteins