ISSN:
0192-253X
Keywords:
Testis ACE
;
positive promoter element
;
in vitro transcription
;
tissue-specificity
;
Life and Medical Sciences
;
Genetics
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Biology
Notes:
Testis angiotensin-converting enzyme (testis ACE) is an isozyme of ACE only expressed by male germ cells during spermiogenesis. It is the result of a strong sperm-specific promoter found within the 12th intron of the somatic ACE gene. Previous studies have localized the boundaries of the mouse testis ACE promoter as being from -91 to -9, relative to the transcriptional start site, and have suggested two important DMA regulatory elements starting at positions -55 and -32. DNA constructs were made in which these motifs were either eliminated or substituted. Each construct was tested for its ability to promote transcription in vitro, using a rat testis nuclear extract. Disruption of either motif reduced in vitro transcription to about 30% of control levels, while mutations of both elements abolished transcription. Two sites were selected inside each motif and altered by point mutation. Each of four constructs, containing a mutation at -51, -48, -30, or -28, transcribed at 29% or less the efficiency of the parent construct. The DNA element at -55, TGAGGTCA, is homologous to a consensus cyclic AMP response element. The motif at -32, TCTTAT, is located at a position analogous to a TATA box. Substitution of the -32 motif with a consensus TATA box sequence, TATAAA, stimulated transcriptional activity about 3-fold. As measured by gel mobility shift, oligonucleotides encompassing the -32 motif and the consensus TATA box formed different DNA-protein complexes. However, the -32 motif oligonucleotide was recognized by nuclear proteins prepared from either liver or testis nuclei. In this example of a tissue-specific promoter that functions only during spermatogenesis, at least two DNA elements act synergistically during in vitro transcription. © 1995 Wiley-Liss, Inc.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/dvg.1020160212
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