J Biol Chem, Vol. 274, Issue 2, 649-656, January 8, 1999
DNA-interacting Proteins in the Spermiogenesis of the Mollusc
Murex brandaris
Carme
Càceres
,
Pepita
Giménez-Bonafé
,
Enric
Ribes¶,
Danielle
Wouters-Tyrou
,
Arlette
Martinage
,
Mostafa
Kouach
,
Pierre
Sautière
,
Sylviane
Muller**,
Jaume
Palau
,
Juan A.
Subirana
,
Luis
Cornudella§§, and
Manel
Chiva
From the
Departament d'Enginyeria Química,
Escola Tècnica Superior d'Enginyers Industrials de Barcelona,
Universitat Politècnica de Catalunya, Diagonal 647, 08028 Barcelona, Spain, the ¶ Departament Biología Cellular Animal
Vegetal, Facultat Biología, Universitat de Barcelona, 08028 Barcelona, Spain,
URA, CNRS 1309, Chimie des Biomolécules,
Institut Pasteur, 59019 Lille, France, ** Institut Biologie
Moléculaire Cellullaire, UPR 9021, CNRS, 67084 Strasbourg,
France, 
Departament d'Enginyeria Química
Bioquímica, Facultat Ciències, Universitat Rovira i
Virgili, 43005 Tarragona, Spain, and §§ Departament
Molecular Cellular Biología, Institut Biología Molecular,
Centro Investigacion y Desarrollo-Consejo Superior de Investigaciones
Científicas, 08028 Barcelona, Spain
Sperm chromatin of Murex brandaris (a
neogastropod mollusc) undergoes a series of structural transitions
during spermiogenesis. The DNA-interacting proteins responsible for
these changes as well as the mature protamines present in the ripe
sperm nucleus have been characterized. The results reveal that
spermiogenic nuclear proteins are protamine precursors that are
subjected to a substantial number of small N-terminal deletions that
gradually modify their overall charge. The composition of mature
protamines is remarkably simple in turn, promoting an efficient and
extremely tight packaging of DNA. The pattern of spermiogenic chromatin condensation in M. brandaris clearly departs from that
corresponding to vertebrate chromatin.
Copyright © 1999 by The American Society for Biochemistry and Molecular Biology, Inc.