PROSITE documentation PDOC00467
Nuclear transition protein 1 signature


In mammals, the second stage of spermatogenesis is characterized by the conversion of nucleosomal chromatin to the compact, nonnucleosomal and transcriptionally inactive form found in the sperm nucleus. This condensation is associated with a double-protein transition. The first transition corresponds to the replacement of histones by several spermatid-specific proteins (also called transition proteins) which are themselves replaced by protamines during the second transition.

Nuclear transition protein 1 (TP1) [1] is one of these spermatid-specific proteins. TP1 is a basic protein of 54 amino-acid residues whose sequence is well conserved in mammalian species. As a signature pattern, we selected a heptapeptide located in positions 28 to 34. This heptapeptide contains five basic residues (Arg or Lys) as well as a tyrosine that could be essential for the destabilization of chromatin by intercalating between the bases of DNA.

Last update:

December 1991 / First entry.


Technical section

PROSITE method (with tools and information) covered by this documentation:

TP1, PS00541; Nuclear transition protein 1 signature  (PATTERN)


1AuthorsChirat F. Martinage A. Briand G. Kouach M. Van Dorsselaer A. Loir M. Sautiere P.
TitleNuclear transition protein 1 from ram elongating spermatids. Mass spectrometric characterization, primary structure and phosphorylation sites of two variants.
SourceEur. J. Biochem. 198:13-20(1991).
PubMed ID2040274

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