title: Temporal association of protamine 1 with the inner nuclear membrane protein lamin B receptor during spermiogenesis.
abstract: During mammalian spermiogenesis, histones are replaced by transition proteins, which are in turn replaced by protamines P1 and P2. P1 protamine contains a short arginine/serine-rich (RS) domain that is highly phosphorylated before being deposited into sperm chromatin and almost completely dephosphorylated during sperm maturation. We now demonstrate that, in elongating spermatids, this phosphorylation is required for the temporal association of P1 protamine with lamin B receptor (LBR), an inner nuclear membrane protein that also possesses a stretch of RS dipeptides at its nucleoplasmic NH(2)-terminal domain. Previous studies have shown that the cellular protein p32 also binds tightly to the unmodified RS domain of LBR. Extending those findings, we now present evidence that p32 prevents phosphorylation of LBR and furthermore that dissociation of this protein precedes P1 protamine association. Our data suggest that docking of protamine 1 to the nuclear envelope is an important intermediate step in spermiogenesis and reveal a novel role for SR protein kinases and p32.
authors.affiliation: Laboratory of Biochemistry, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki 54 124, Greece.
authors.forename: Ilias
authors.initials: I
authors.lastname: Mylonis
authors.forename: Victoria
authors.initials: V
authors.lastname: Drosou
authors.forename: Stefano
authors.initials: S
authors.lastname: Brancorsini
authors.forename: Eleni
authors.initials: E
authors.lastname: Nikolakaki
authors.forename: Paolo
authors.initials: P
authors.lastname: Sassone-Corsi
authors.forename: Thomas
authors.initials: T
authors.lastname: Giannakouros
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D006801:Humans; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D009685:Nuclear Envelope / Q000378:metabolism; D010766:Phosphorylation; D011479:Protamines / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D018160:Receptors, Cytoplasmic and Nuclear / Q000378:metabolism*; D013091:Spermatogenesis; D000097682:Lamin B Receptor
chemical_list: D011479:Protamines; D018160:Receptors, Cytoplasmic and Nuclear; D000097682:Lamin B Receptor; C082073:PRM1 protein, human; C513176:Prm1 protein, mouse; C513174:Prm1 protein, rat