Showing papers by "Marta Palmieri published in 1988"

Structure of the bovine pancreatic ribonuclease gene: the unique intervening sequence in the 5′ untranslated region contains a promoter-like element

Abstract: Although pancreatic ribonucleases are extensively studied proteins, little information is available on nucleic acids coding for these enzymes. Here, for the first time, the structure of a gene coding for such an enzyme, the well known bovine pancreatic ribonuclease, is reported. The coding region of this gene is devoid of introns, whereas the 5' untranslated sequence of the pancreatic transcript contains an intron of 735 nucleotides. This intervening sequence is endowed with signals (CAAT and TATA boxes) which might act as regulatory elements. The structural organization of this gene suggests that the sequence coding for the bovine pancreatic ribonuclease might be expressed under the control of two different promoters.

Expression of opioid genes in bovine seminal vesicles.

Abstract: In seminal vesicles, the organ producing most of seminal plasma in the bovine species, the proopiomelanocortin and the proenkephalin genes are transcribed and translated, and their translation products processed into opioid peptides, which are secreted into the seminal plasma. By using a micro-organ preparation of seminal vesicles we found that, after 20 h of incubation with labelled methionine, a multiplicity of opioids was produced. Among these, [Metlenkephalin and p-endorphin were positively indentified, whereas in the newly formed secretion only [Metlenkephalin was detected. This may be correlated to the finding that the concentration of p-endorphin in an extract of seminal plasma was one order of magnitude lower than that of [Leulenkephalin and [Metlenkephalin. These findings expand the picture of the presence of opiod peptides in the male reproductive tract, indicating that they should have a role(s) in the physiology of reproduction, not only in the hypothalamuspituitary-gonadal axis, determining the reproductive potential, but also in the so-termed sex accessory glands, determining the actual events leading to reproduction. To our knowledge this is also the first case studied of opioid peptides produced as exocrine hormones. Opioid peptides are produced through post-translational proteolytic processing of three precursor polyproteins (see [l] for a review): pro-opiomelanocortin, proenkephalin and prodynorphin, which appear to be coded by unique genes in all the genomes so far investigated [l, 21. These genes have been found to be expressed in the central nervous system and the pituitary of all the vertebrate species examined, but it is becoming increasingly clear that the expression of these genes occurs also in non-neural tissues. This is not surprising, considering the diverse physiological functions affected by opioid peptides and the variety of biological effects they exert [3]. Reports have appeared of immunocytochemical and radioimmunological studies revealing the presence of opioid imtnunoreactivity in several tissues, including the male reproductive tract [4 - 71. Further, transcription of opioid genes has been demonstrated in several organs and tissues [S, 91. However, direct correlations between transcription of the opioid genes in non-neural tissues and occurrence of opioids in these tissues have been obtained only in a few cases, such as those of mammal adrenal medulla [lo], rodent placenta and ovary [I1 - 131 and rat heart [14]. As for the male reproductive tract, all three opioid genes have been found to be expressed in testis, epididymis and vas deferens [15 - 191. However, little attention has been given so far to the male 'accessory' sex glands, such as prostate and seminal vesicles, which do play essential roles, especially in the production of the fluid part of semen and in the ejaculation event [21, 221. We report here that in the seminal vesicles of the bovine species, in which the seminal plasma is virtually a product of