Histone H4 hyperacetylation and rapid turnover of its acetyl groups in transcriptionally inactive rooster testis spermatids

Abstract

In order to study the relationship between acetylation of histones, chromatin structure and gene activity, the distribution and turnover of acetyl groups among nucleosomal core histones and the extent of histone H4 acetylation were examined in rooster testis cell nuclei at different stages of spermatogenesis. Histone H4 was the predominant acetylated histone in mature testes. Hyperacetylation of H4 and rapid turnover of its acetyl groups are not univocally correlated with transcriptional activity since they were detected in both genetically active testicular cells and genetically inactive elongated spermatids. During the transition from nucleohistone to nucleoprotamine in elongated spermatids the chromatin undergoes dramatic structural changes with exposition of binding sites on DNA (1). Hyperacetylation of H4 and rapid turnover of its acetyl groups could be correlated with the particular conformation of chromatin in elongated spermatids and might represent a necessary condition for binding of chromosomal proteins to DNA.

RNA polymerase activity and template activity of chromatin after butyrate induced hyperacetylation of histones inPhysarum

“…However these data represent only circumstantial evidence and there are several recent reports, which do not favor this concept; e.g. in rat liver nuclei transcribing chromatin was not enriched with acetylated histones (36); in Drosophila embryos no correlation between histone acetylation and transcription could be established (37); during spermatogenesis H4 (hyper)acetylation obviously serves other purposes than transcriptional activity as demonstrated in rooster (38) as well as in trout (39). Results with the SV-40 minichromosome (40) and with HTC-cells (41) also cast doubt on the theory of acetylation-transcription coupling.…”

Proteomic identification of human sperm proteins

“…Among nuclear proteins identified, one surprise has been the identification of RuvB-like 1 protein known to have ATPase and DNA helicase activities and to be part of the NuA4 histone acetyltransferase complex. Extensive histone hyperacetylation is known to take place during the nucleo- histone to nucleoprotamine transition in spermatogenesis [44,45]. Also, upon fertilization, a new wave of histone hyperacetylation takes place concomitant to the paternal nucleosome formation.…”

A multi-faceted approach to understanding male infertility: gene mutations, molecular defects and assisted reproductive techniques (ART)

“…At fertilization, the mature sperm cells are packaged densely with protamines, whereas maternal genome is packaged with histones. Subsequently, upon fertilization, the highly compact nucleoprotamine structure must be unpacked and reorganized into a nucleosomal structure [165]. Recent studies have shown that some epigenetic errors in these processes are a possible cause of male infertility.…”