The replacement H3.3 histone gene in Paracentrotus lividus sea urchin: structure and regulatory elements

We have isolated the Paracentrotus lividus sea urchin H3.3 histone gene and characterized the nucleotide sequences of the gene and its proximal promot er. Band shift experiments showed that two cAMP/PMA responsive elements (CR E/TRE), present in the proximal promoter, bind nuclear factors present in e mbryos at the blastula and gastrula stages (CRE1) and at the blastula stage (CRE2). The putative H3.3 coding region activating sequences (CRAS) failed to bind nuclear factors while the corresponding elements of the two replic ation-dependent genes (H3L, and late H3) clearly recognized nuclear protein s. These results suggest some role of the CRE/TRE elements but not CRAS ele ments in the transcriptional regulation of the replication-independent hist one genes in invertebrates. (C) 2001 Elsevier Science B.V. All rights reser ved.