| Title: | Prm3p is a pheromone-induced peripheral nuclear envelope protein required for yeast nuclear fusion |
| Author(s): | Shen S; Tobery CE; Rose MD; |
| Address: | "Department of Molecular Biology, Princeton University, Princeton, NJ 08544-1014, USA" |
| ISSN/ISBN: | 1939-4586 (Electronic) 1059-1524 (Print) 1059-1524 (Linking) |
| Abstract: | "Nuclear membrane fusion is the last step in the mating pathway of the yeast Saccharomyces cerevisiae. We adapted a bioinformatics approach to identify putative pheromone-induced membrane proteins potentially required for nuclear membrane fusion. One protein, Prm3p, was found to be required for nuclear membrane fusion; disruption of PRM3 caused a strong bilateral defect, in which nuclear congression was completed but fusion did not occur. Prm3p was localized to the nuclear envelope in pheromone-responding cells, with significant colocalization with the spindle pole body in zygotes. A previous report, using a truncated protein, claimed that Prm3p is localized to the inner nuclear envelope. Based on biochemistry, immunoelectron microscopy and live cell microscopy, we find that functional Prm3p is a peripheral membrane protein exposed on the cytoplasmic face of the outer nuclear envelope. In support of this, mutations in a putative nuclear localization sequence had no effect on full-length protein function or localization. In contrast, point mutations and deletions in the highly conserved hydrophobic carboxy-terminal domain disrupted both protein function and localization. Genetic analysis, colocalization, and biochemical experiments indicate that Prm3p interacts directly with Kar5p, suggesting that nuclear membrane fusion is mediated by a protein complex" |
| Keywords: | "Amino Acid Sequence Conserved Sequence Genes, Fungal Hydrophobic and Hydrophilic Interactions Membrane Fusion/*drug effects Membrane Proteins/chemistry/metabolism Molecular Sequence Data Mutation/genetics Nuclear Envelope/drug effects/*metabolism/ultrastr;" |
| Notes: | "MedlineShen, Shu Tobery, Cynthia E Rose, Mark D eng R01 GM037739/GM/NIGMS NIH HHS/ R01 GM037739-22/GM/NIGMS NIH HHS/ GM-37739/GM/NIGMS NIH HHS/ Research Support, N.I.H., Extramural 2009/03/20 Mol Biol Cell. 2009 May; 20(9):2438-50. doi: 10.1091/mbc.e08-10-0987. Epub 2009 Mar 18" |
