Tissue-specific protein-DNA interactions of the mouse protamine 2 gene promoter

Abstract

During spermiogenesis, the haploid phase of spermatogenesis, the genome is packaged into a highly compacted form and this process requires replacement of histones by protamines. In the mouse, protamines are encoded by two genes, which are transcriptionally regulated in testis. To understand the regulation of transcription of the mouse protamine 2 (mP2) gene, the tissue-distribution of sequence-specific interactions between nuclear proteins and promoter DNA sequences have been analyzed. Protein binding to the promoter region from -370 to +65 was studied using DNase I footprinting and gel shift assays. Five protein binding sites were identified, which are recognized by nuclear proteins from either testis or liver. Site 1 from -64 to -48, contains part of a cAMP responsive element (CRE), which in testis is recognized by CREM tau, an activator of post-meiotic transcription. Testicular protein(s) also binds to three other promoter domains: site 2, -87 to -67, a region containing a CAAT box, and sites 4 and 5, -239 to -210 and -328 to -311, sequences with similarity to consensus steroid hormone responsive elements (HRE). In contrast, interactions between the mP2 promoter and nuclear factors from liver, a tissue in which the mP2 gene is not transcribed, are observed at sites 1, 2, and 4, as well as at an additional region at site 3, -202 to -175. Because occupancy at site 3 appears to correlate with inactivation of the gene in non-testicular tissues, whereas testicular protein binding at site 5 appears to be associated with active transcription, we conclude that the mP2 promoter displays intricate tissue-specific patterns of protein/DNA interactions at key regulatory elements.

A global but stable change in HeLa cell morphology induces reorganization of DNA structural loop domains within the cell nucleus

“…It is worth mention that the PRM2 gene remains non‐expressed in the HeLa DMSO‐treated cells, while the c‐myc gene is expressed at the same level than in the control HeLa cells (our unpublished results), which was likely to be expected, considering that it has been shown that the positions of genes relative to the NM mediated by high‐salt resistant structural attachments are not related to transcription status and so the genes display transcription levels that are independent of their position relative to the NM [Maya‐Mendoza et al, 2003, 2004]. Moreover, tissue specific expression of genes such as PRM2 depends on very specific local chromatin changes mediated by a number of chromatin‐modifying and DNA‐binding proteins, some that are likely to be available only in the specific differentiated cells where the particular gene expression is needed [Ha et al, 1997; Kramer et al, 1998]. Nevertheless, our results support the hypothesis that mechanical information transduced by cytoskeleton and nucleoskeleton modifies the topological relationships between the chromatin and the nuclear substructure [Aranda‐Anzaldo, 1989].…”

Preservation of Spermatogenesis in Spinal Cord Injured Rats With Exogenous Testosterone. Relationship With Serum Testosterone Levels and Cellular Localization of cAMP Responsive Element Modulator

“…Such effects thus mediate the effects of androgen on spermatogenesis. However, presence of AR and androgen‐binding protein (ABP) in spermatogenic cells (Vornberger et al, 1994; Joseph et al, 1997), stimulation of protein synthesis in spermatocytes by the T/ABP complex (Gerard, 1995), and presence of a hormone‐responsive element (HRE) in the promoter of genes that encode germ cell‐specific proteins (Bonny et al, 1998; Ha et al, 1997) suggest that T might also affect spermatogenic cells directly. In addition, recent studies have demonstrated that cAMP signaling might also mediate some effect of androgen, especially in those cells lacking functional AR (Heinline and Chang, 2002).…”

Spinal Cord Contusion Impairs Sperm Motility in the Rat Without Disrupting Spermatogenesis

“…Such changes could disrupt the differentiation of spermatogenic cells and could result in the formation of sperm with abnormal morphology or function. In this regard, the promoter of Pm‐1 and LDHC genes contains the putative cAMP response element (Ha et al, 1997; Bonny et al, 1998) and therefore could be affected by abnormal cAMP signaling. Premature translation of Pm‐1 in the transgenic mouse has been found to result in precocious condensation of spermatid nuclei and arrest of spermatogenesis at the spermatid stages (Lee et al, 1995).…”