title: Changing subcellular localization of nuclear transport factors during human spermatogenesis.
abstract: Spermatogenesis requires progressive changes in gene expression mediated by hormonal and local factors. Regulated macromolecular movement between nuclear and cytoplasmic compartments enables these essential responses to changing extracellular cues, and dynamic production of the nucleocytoplasmic transporters and importin proteins, throughout gametogenesis in rodents implicates them as key mediators of germline differentiation. We examined normal adult human testis expression profiles of six importins plus five additional proteins involved in nucleocytoplasmic transport. Although most were detected in the nucleus during germline differentiation, importin α4 was exclusively observed in Sertoli and germ cell cytoplasm. Many proteins were present in round spermatid nuclei (importins α1, α3, β1, β3; exportin-1, Nup62, Ran, RanBP1, RCC1), and remarkable intense nuclear and/or nuclear-associated signals were detected for importin α1, importin α3 and Nup62 in spermatocytes. This study identifies conserved aspects of nucleocytoplasmic transport during spermatogenesis and extends our knowledge of the dynamic presence of these proteins, which indicates that they contribute to germ cell-specific cargo trafficking and potentially to other functions during human spermatogenesis. We also demonstrate for the first time that importin α3 is nuclear in spermatocytes, when exportin-1 is cytoplasmic, suggesting that nuclear transport is altered during meiosis.
authors.affiliation: Department of Biochemistry and Molecular Biology, Monash University, Clayton, Victoria, Australia.
authors.forename: P A F
authors.initials: PA
authors.lastname: Whiley
authors.forename: Y
authors.initials: Y
authors.lastname: Miyamoto
authors.forename: R I
authors.initials: RI
authors.lastname: McLachlan
authors.forename: D A
authors.initials: DA
authors.lastname: Jans
authors.forename: K L
authors.initials: KL
authors.lastname: Loveland
mesh_terms: D021581:Active Transport, Cell Nucleus; D000818:Animals; D002454:Cell Differentiation; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D003593:Cytoplasm / Q000378:metabolism; D015870:Gene Expression; D005786:Gene Expression Regulation; D005854:Germ Cells / Q000166:cytology; D006367:HeLa Cells; D006801:Humans; D028884:Karyopherins / Q000096:biosynthesis / Q000378:metabolism; D008297:Male; D008562:Membrane Glycoproteins / Q000096:biosynthesis; D051379:Mice; D008810:Mice, Inbred C57BL; D028861:Nuclear Pore Complex Proteins / Q000096:biosynthesis; D029543:Nucleocytoplasmic Transport Proteins / Q000378:metabolism*; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism; D013087:Spermatids / Q000378:metabolism; D013090:Spermatocytes / Q000378:metabolism*; D013091:Spermatogenesis; D000097606:Exportin 1 Protein
chemical_list: D028884:Karyopherins; D008562:Membrane Glycoproteins; D028861:Nuclear Pore Complex Proteins; D029543:Nucleocytoplasmic Transport Proteins; D018160:Receptors, Cytoplasmic and Nuclear; D000097606:Exportin 1 Protein; C049312:nuclear pore protein p62