Mutation of the small acidic tract A1 drastically reduces nucleoplasmin activity.
Xenopus laevis nucleoplasmin is a molecular chaperone that mediates sperm decondensation and nucleosome assembly. Nucleoplasmin has three acidic tracts (A1, A2 and A3) and until recent years the long polyglutamic tract A2 was thought to be the binding site for basic proteins. However, the latest publications in this field show that neither A2 nor A3 is indispensable for histone and sperm-specific protein binding. In this work, we show that the mutation of only four acidic amino acid residues of the small A1 tract drastically reduces nucleoplasmin decondensing activity, pointing out this region as the potential binding site for sperm proteins.
Salvany
Lara
L
Departament d'Enginyeria Química, ETSEIB, Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Spain.
Chiva
Manel
M
Arnan
Carme
C
Ausió
Juan
J
Subirana
Juan A
JA
Saperas
Núria
N
D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D001492:Bass; D008297:Male; D016297:Mutagenesis, Site-Directed; D009687:Nuclear Proteins / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D056489:Nucleoplasmins; D010750:Phosphoproteins / Q000737:chemistry* / Q000235:genetics* / Q000502:physiology; D011994:Recombinant Proteins / Q000737:chemistry; D013094:Spermatozoa / Q000737:chemistry / Q000502:physiology; D029867:Xenopus Proteins / Q000737:chemistry / Q000235:genetics; D014982:Xenopus laevis / Q000502:physiology
D009687:Nuclear Proteins; D056489:Nucleoplasmins; D010750:Phosphoproteins; D011994:Recombinant Proteins; D029867:Xenopus Proteins