title: Identification of genes encoding putative nucleoporins and transport factors in the fission yeast Schizosaccharomyces pombe: a deletion analysis.
abstract: In a systematic approach to study genes that are related to nucleocytoplasmic trafficking in the fission yeast Schizosaccharomyces pombe, the open reading frames (ORFs) of 26 putative nucleoporins and transport factors were deleted. Here we report the initial characterization of these deletion mutants. Of the 26 putative genes deleted, 14 were found to be essential for viability. Null mutations of essential genes resulted in failure to either complete one round or to sustain cell division. Four of the 14 essential genes, SPBC582.11c, SPBC17G9.04c, SPBC3B9.16c and SPCC162.08c, encode putative nucleoporins and a myosin-like protein with homologues NUP84, NUP85, NUP120 and MLP1, respectively, that are not required for viability in Saccharomyces cerevisiae, suggesting that their gene products perform critical functions in Sz. pombe. On the basis of combined drug sensitivity assays and genetic analysis we have identified five non-essential null mutants that were hypersensitive to the microtubule depolymerizing drug thiabendazole (TBZ) and exhibited a cut phenotype upon TBZ treatment, suggesting possible involvement in microtubule function. Three of the corresponding ORFs, SPCC18B5.07c, nup40 and SPAC1805.04, encode putative nucleoporins with low similarity to the S. cerevisiae nucleoporins NUP2p, NUP53p and NUP133p, respectively. Further genetic analysis revealed that one of the nucleoporin genes, nup40, and another gene, SPCC1322.06, encoding a putative importin-beta/Cse1p superfamily protein may have a spindle checkpoint function.
authors.affiliation: Laboratory of Nucleopore Biology, Institute of Molecular and Cell Biology, National University of Singapore, 30 Medical Drive, Singapore 117609.
authors.forename: Xue Qin
authors.initials: XQ
authors.lastname: Chen
authors.forename: Xianming
authors.initials: X
authors.lastname: Du
authors.forename: Jianhua
authors.initials: J
authors.lastname: Liu
authors.forename: Mohan K
authors.initials: MK
authors.lastname: Balasubramanian
authors.forename: David
authors.initials: D
authors.lastname: Balasundaram
mesh_terms: D002352:Carrier Proteins / Q000235:genetics* / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry; D017353:Gene Deletion; D020043:Genes, Essential / Q000235:genetics / Q000502:physiology; D005800:Genes, Fungal / Q000235:genetics / Q000502:physiology; D049452:Green Fluorescent Proteins; D017404:In Situ Hybridization, Fluorescence; D007211:Indoles / Q000737:chemistry; D008164:Luminescent Proteins / Q000737:chemistry; D008856:Microscopy, Fluorescence; D016254:Mutagenesis, Insertional; D028861:Nuclear Pore Complex Proteins / Q000235:genetics* / Q000378:metabolism; D016366:Open Reading Frames; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D012568:Schizosaccharomyces / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism; D029702:Schizosaccharomyces pombe Proteins / Q000235:genetics* / Q000378:metabolism; D013827:Thiabendazole / Q000494:pharmacology
chemical_list: D002352:Carrier Proteins; D005456:Fluorescent Dyes; D007211:Indoles; D008164:Luminescent Proteins; D028861:Nuclear Pore Complex Proteins; C576664:Nup120 protein, S pombe; D012333:RNA, Messenger; D029702:Schizosaccharomyces pombe Proteins; D049452:Green Fluorescent Proteins; C007293:DAPI; D013827:Thiabendazole