title: Nup153 affects entry of messenger and ribosomal ribonucleoproteins into the nuclear basket during export.
abstract: A specific messenger ribonucleoprotein (RNP) particle, Balbiani ring (BR) granules in the dipteran Chironomus tentans, can be visualized during passage through the nuclear pore complex (NPC). We have now examined the transport through the nuclear basket preceding the actual translocation through the NPC. The basket consists of eight fibrils anchored to the NPC core by nucleoprotein Nup153. On nuclear injection of anti-Nup153, the transport of BR granules is blocked. Many granules are retained on top of the nuclear basket, whereas no granules are seen in transit through NPC. Interestingly, the effect of Nup153 seems distant from the antibody-binding site at the base of the basket. We conclude that the entry into the basket is a two-step process: an mRMP first binds to the tip of the basket fibrils and only then is it transferred into the basket by a Nup153-dependent process. It is indicated that ribosomal subunits follow a similar pathway.
authors.affiliation: Department of Cell and Molecular Biology, Medical Nobel Institute, Karolinska Institutet, S-171 77 Stockholm, Sweden.
authors.forename: Teresa
authors.initials: T
authors.lastname: Soop
authors.forename: Birgitta
authors.initials: B
authors.lastname: Ivarsson
authors.forename: Birgitta
authors.initials: B
authors.lastname: Björkroth
authors.forename: Nathalie
authors.initials: N
authors.lastname: Fomproix
authors.forename: Sergej
authors.initials: S
authors.lastname: Masich
authors.forename: Volker C
authors.initials: VC
authors.lastname: Cordes
authors.forename: Bertil
authors.initials: B
authors.lastname: Daneholt
mesh_terms: D000818:Animals; D001483:Base Sequence; D002467:Cell Nucleus / Q000378:metabolism*; D002683:Chironomidae / Q000378:metabolism*; D017931:DNA Primers; D016253:Microscopy, Immunoelectron; D028861:Nuclear Pore Complex Proteins / Q000378:metabolism*; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012335:RNA, Ribosomal / Q000378:metabolism; D012261:Ribonucleoproteins / Q000235:genetics / Q000378:metabolism
chemical_list: D017931:DNA Primers; D028861:Nuclear Pore Complex Proteins; D012333:RNA, Messenger; D012335:RNA, Ribosomal; D012261:Ribonucleoproteins