Transcriptional cascades during spermatogenesis: pivotal role of CREM and ACT

Mol Cell Endocrinol. 2001 Jun 20;179(1-2):17-23. doi: 10.1016/s0303-7207(01)00463-4.


The gene CREM plays key physiological and developmental roles within the hypothalamic--pituitary--gonadal axis. We have previously shown that CREM is highly expressed in male postmeiotic cells. Spermiogenesis is a complex process by which postmeiotic male germ cells differentiate into mature spermatozoa. CREM regulates the expression of a number of post-meiotic genes involved in the process of spermiogenesis. Using homologous recombination we have generated CREM-mutant mice that display a complete block at the first step of spermiogenesis. The molecular mechanism by which CREM elicits its regulatory function involves ACT (Activator of CREM in Testis), a testis-specific coactivator constituted by a repeat of four and half LIM domains. ACT is coordinately expressed with CREM, associates with it and confers a powerful transcriptional activation function. It is able to bypass the classical requirement of CREM phosphorylation and recruiting of CBP.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Cyclic AMP Response Element Modulator
  • DNA-Binding Proteins / genetics
  • DNA-Binding Proteins / physiology*
  • Gene Expression Regulation / genetics
  • Humans
  • LIM Domain Proteins
  • Male
  • Repressor Proteins*
  • Signal Transduction / genetics
  • Signal Transduction / physiology
  • Spermatogenesis / genetics
  • Spermatogenesis / physiology*
  • Spermatozoa / physiology
  • Transcription Factors / genetics
  • Transcription Factors / physiology*
  • Transcriptional Activation / genetics*


  • DNA-Binding Proteins
  • FHL5 protein, human
  • Fhl5 protein, mouse
  • LIM Domain Proteins
  • Repressor Proteins
  • Transcription Factors
  • activator of CREM in testis (ACT)
  • Cyclic AMP Response Element Modulator