title: Nucleoplasmin interaction with protamines. Involvement of the polyglutamic tract.
abstract: Different recombinant forms of nucleoplasmin including truncations at the carboxyl-terminal end of the molecule (r-NP121, r-NP142) have been expressed and purified. All of them were found to oligomerize, forming pentameric complexes which, according to their hydrodynamic properties, can be modeled by oblate ellipsoids of constant width. In this model, the highly charged carboxyl ends appear to be arranged around a pentameric core along the plane defined by the major axes of the ellipsoid. Importantly, all the recombinant forms appear to be able to decondense protamine-containing sperm nuclei. However, although the stoichiometry with which protamines bind to these forms appears to be constant (2.5 mol of protamine/mol of nucleoplasmin pentamer), the efficiency with which they remove protamines from the sperm DNA decreases in the following order: o-NP > r-NP142 > or = r-NP >> r-NP121. Therefore, the main polyglutamic tract of nucleoplasmin (which is absent in r-NP121), while enhancing the efficiency of protamine removal, is not indispensable for sperm chromatin decondensation in the biological model we have used.
authors.affiliation: Departament d'Enginyeria Química, ETSEIB, Universitat Politècnica de Catalunya, Diagonal 647, Barcelona E-08028, Spain.
authors.forename: Cèlia
authors.initials: C
authors.lastname: Prieto
authors.forename: Núria
authors.initials: N
authors.lastname: Saperas
authors.forename: Carme
authors.initials: C
authors.lastname: Arnan
authors.forename: Melissa H
authors.initials: MH
authors.lastname: Hills
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Wang
authors.forename: Manel
authors.initials: M
authors.lastname: Chiva
authors.forename: Rosa
authors.initials: R
authors.lastname: Aligué
authors.forename: Juan A
authors.initials: JA
authors.lastname: Subirana
authors.forename: Juan
authors.initials: J
authors.lastname: Ausió
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001492:Bass; D002025:Bufonidae; D002467:Cell Nucleus / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D056489:Nucleoplasmins; D010750:Phosphoproteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011099:Polyglutamic Acid / Q000737:chemistry* / Q000502:physiology*; D011479:Protamines / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding / Q000235:genetics; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D017384:Sequence Deletion; D013050:Spectrometry, Fluorescence; D013094:Spermatozoa / Q000737:chemistry / Q000378:metabolism; D014982:Xenopus laevis / Q000235:genetics
chemical_list: D009687:Nuclear Proteins; D056489:Nucleoplasmins; D010750:Phosphoproteins; D011479:Protamines; D011994:Recombinant Proteins; D011099:Polyglutamic Acid