Nuclear basic protein transition during sperm differentiation. Amino acid sequence of a spermatid-specific protein from the dog-fish Scylliorhinus caniculus.
During dog-fish spermatogenesis, chromatin undergoes a continuous processing which involves two basic protein transitions: the first from somatic-type histones to spermatid-specific proteins and the second leading to protamines. Two spermatid-specific proteins S1 and S2 were isolated from nuclei of spermatid-enriched testis zone and the amino acid sequence of S1 has been determined. S1 contains 87 amino acids and has a molecular mass of 11179 Da. It is mainly characterized by a high content of basic residues (45%) and the presence of one residue of cysteine. Its primary structure shows that the N-terminal half is highly basic while the hydrophobic residues are preferentially localized in the C-terminal region. Three forms of S1 are present in testis which correspond to di-, mono- and nonphosphorylated molecules. This spermatid-specific protein shares no common structural feature with either histones and dog-fish protamines or rat spermatid-specific protein which has been previously described.
Chauvière
M
M
Laboratoire de Biologie Cellulaire, Université Paris-Val de Marne, Créteil, France.
Martinage
A
A
Briand
G
G
Sautière
P
P
Chevaillier
P
P
D000469:Alkaline Phosphatase / Q000378:metabolism; D000595:Amino Acid Sequence; D000818:Animals; D002868:Chromosomal Proteins, Non-Histone; D004284:Dogfish / Q000378:metabolism*; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000032:analysis*; D010446:Peptide Fragments; D010766:Phosphorylation; D012689:Sequence Homology, Nucleic Acid; D012754:Sharks / Q000378:metabolism*; D013087:Spermatids / Q000032:analysis*; D013091:Spermatogenesis; D013737:Testis / Q000166:cytology
D002868:Chromosomal Proteins, Non-Histone; D009687:Nuclear Proteins; D010446:Peptide Fragments; C053886:spermatid transition proteins; D000469:Alkaline Phosphatase