H4K5 Butyrylation Coexist with Acetylation during Human Spermiogenesis and Are Retained in the Mature Sperm Chromatin

Int J Mol Sci. 2022 Oct 17;23(20):12398. doi: 10.3390/ijms232012398.

Abstract

Male germ cells experience a drastic chromatin remodeling through the nucleo-histone to nucleo-protamine (NH-NP) transition necessary for proper sperm functionality. Post-translational modifications (PTMs) of H4 Lys5, such as acetylation (H4K5ac), play a crucial role in epigenetic control of nucleosome disassembly facilitating protamine incorporation into paternal DNA. It has been shown that butyrylation on the same residue (H4K5bu) participates in temporal regulation of NH-NP transition in mice, delaying the bromodomain testis specific protein (BRDT)-dependent nucleosome disassembly and potentially marking retained nucleosomes. However, no information was available so far on this modification in human sperm. Here, we report a dual behavior of H4K5bu and H4K5ac in human normal spermatogenesis, suggesting a specific role of H4K5bu during spermatid elongation, coexisting with H4K5ac although with different starting points. This pattern is stable under different testicular pathologies, suggesting a highly conserved function of these modifications. Despite a drastic decrease of both PTMs in condensed spermatids, they are retained in ejaculated sperm, with 30% of non-colocalizing nucleosome clusters, which could reflect differential paternal genome retention. Whereas no apparent effect of these PTMs was observed associated with sperm quality, their presence in mature sperm could entail a potential role in the zygote.

Keywords: H4K5; acetylation; butyrylation; epigenetic regulation; sperm; sperm chromatin; spermatogenesis.

MeSH terms

  • Acetylation
  • Animals
  • Chromatin Assembly and Disassembly
  • Chromatin* / metabolism
  • Histones / metabolism
  • Humans
  • Male
  • Mice
  • Nucleosomes* / metabolism
  • Protamines / metabolism
  • Protein Processing, Post-Translational
  • Semen / metabolism
  • Spermatids / metabolism
  • Spermatogenesis / physiology
  • Spermatozoa / metabolism

Substances

  • Chromatin
  • Nucleosomes
  • Histones
  • Protamines

Grants and funding

This research was funded by grants PI16/00346 and PI20/00936 to R.O. from the ‘Ministerio de Economía y Competividad’ (Spain, ‘fondos FEDER, una manera de hacer Europa’). This publication is also based upon work from COST Action CA20119 (ANDRONET) supported by COST ((European Cooperation in Science and Technology) www.cost.eu, accessed on 6 September 2022). J.C. was supported by the Sara Borrell Postdoctoral Fellowship, ‘Acción Estratégica en Salud’, CD17/00109. J.C. is a Serra Húnter fellow (Universitat de Barcelona, Generalitat de Catalunya). A.I. is supported by a fellowship from the ‘Ministerio de Economía, Industria y Competitividad’ (Spain), ‘Acción Estratégica en Salud, contrato Predoctoral de Formación en Investigación en Salud’ (PFIS, FI17/00224). F.B. received a grant from the Ministerio de Educación, Cultura y Deporte para la Formación de Profesorado Universitario (Spain) (FPU15/02306). M.J. was supported by the Government of Catalonia (Generalitat de Catalunya, pla estratègic de recerca i innovació en salut, PERIS 2016-2020, SLT002/16/00337). L.D. and K.K. were supported by Czech Science Foundation (GACR GJ20-17403Y) to L.D. and GC20-20217J to K.K., project BIOCEV (CZ.1.05/1.1.00/02/0109) from the ERDF and the Institute of Biotechnology RVO:86652036 to L.D. and K.K.