title: cDNA cloning and characterization of Npap60: a novel rat nuclear pore-associated protein with an unusual subcellular localization during male germ cell differentiation.
abstract: We have cloned and characterized a cDNA, Npap60, encoding a rat nuclear pore-associated protein. The 3-kb cDNA was obtained by antibody screening of a rat testis expression library. The predicted NPAP60 contains 381 amino acids with a composition of 25.6% charged residues and is highly hydrophilic. The Npap60 gene appears to be conserved in mouse, rat, and human. Immunofluorescence studies with anti-NPAP60 fusion protein antibody show that the NPAP60 protein colocalizes with nuclear pore complexes in RAT1A cells. The expression of Npap60 is about 10-20 times higher in rat testis than in somatic tissues. The subcellular localization of NPAP60 protein changes dramatically during male germ cell differentiation, from nuclear pore complex-like staining in spermatocytes to whole nucleus staining in spermatids and finally to a nuclear surface staining in mature spermatozoa. These changes are temporally and spatially related to nuclear reorganization during male germ cell differentiation.
authors.affiliation: Molecular Biology Program, University of Southern California, Los Angeles, California 90089-1340, USA.
authors.forename: F
authors.initials: F
authors.lastname: Fan
authors.forename: C P
authors.initials: CP
authors.lastname: Liu
authors.forename: O
authors.initials: O
authors.lastname: Korobova
authors.forename: C
authors.initials: C
authors.lastname: Heyting
authors.forename: H H
authors.initials: HH
authors.lastname: Offenberg
authors.forename: G
authors.initials: G
authors.lastname: Trump
authors.forename: N
authors.initials: N
authors.lastname: Arnheim
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002454:Cell Differentiation; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics* / Q000302:isolation & purification; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000378:metabolism*; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins / Q000235:genetics*; D018272:Porins / Q000235:genetics*; D051381:Rats; D016415:Sequence Alignment; D013094:Spermatozoa / Q000166:cytology / Q000378:metabolism*
chemical_list: D018076:DNA, Complementary; D028861:Nuclear Pore Complex Proteins; D009687:Nuclear Proteins; C105412:Nup50 protein, mouse; C484544:Nup50 protein, rat; D018272:Porins