Primary structure and assignment to chromosome 6 of three related rat genes encoding liver serine protease inhibitors

Transcriptional Repression, a Novel Function for 3' Untranslated Regions

“…As judged by its almost total lack of effect on both the basal activity of the SV40 early promoter and the aldolase B promoter, and on dexamethasone and lL-6 activation of the spi 2.3 promoter, it neither appears to interfere with elements of the basic transcriptional machinery nor seems to significantly affect the stability of the cat message or protein. The data presented here rather support the notion that the silencer interferes with the function of two types of 5' cis-acting elements, previously shown to regulate basal transcription and GH-dependent transcription of the spi 2.1 promoter [3]; the first is the GAGA box which is a key control element [3] fully conserved in all three spi genes [4]. The hypothesis that the spi 2.3-specific 3' UTR silencer modulates the GAGA box function is based on the following rationale: (a) the effects of the silencer on both basal and GH-activated transcription of intact, maximally active spi 2.1 and spi 2.3 promoters are faithfully reproduced by mutating the GAGA box; (b) more importantly, the GH-dependent activity of a spi 2.3 promoter construct harboring only the first GH-response element (GHRE-I), which therefore depends exclusively on the GAGA box [3], is totally abolished by the spi 2.3-specific 3' UTR or by mutating the GAGA box.…”

“…Indeed, if in both cases such a mutation similarly inhibits basal and GH-dependent activated transcription, it only partly reduces transcriptional stimulation of spi 2.3 promoter by dexamethasone (this study), whereas it totally prevents glucocorticoid activation of the spi 2.1 promoter /3]. Although we cannot, at this stage, offer a definitive explanation, this may simply reflect the punctual differences in the nucleotide composition of the two promoters [4], more specifically those existing in the region (i.e. GRE; Fig.…”

“…Since, in the spi 2.3 promoter, the site corresponding to the spi 2.1 GHRE-I1 is mutated, its activation by GH only depends on the activity of the single active GHRE present within this promoter, namely GHRE-I (Fig. l), which contains the conserved purine-rich sequence called the GAGA box [4]. We have recently demonstrated, using spi 2.1 promoter constructs, that the GH-induced activity of GHRE-I exclusively depends on the integrity and position of the GAGA box [3}.…”

“…Plasmids used for transfection were derived from promoterless vectors harboring the chloramphenicol acetyltransferase gene (cat), pEMBL [lo] or pBLCAT [ll], or the luciferase gene (luc), and pGL2 basic (Promega). Wild-type or mutated fragments derived from spi 2.1 or spi 2.3 promoters [4] were generated using the PCR method [12] and cloned upstream from the cat-coding or luc-coding sequences. Site-specific mutations were introduced using asymmetric PCR [13].…”

Patchwork‐structure serpins from silkworm (Bombyx mori) larval hemolymph

“…A clear junction the in amino acid sequence exists between amino acids 336 and 337 in both serpins. Such a junction has already been found in rodent serpins, based on their nucleotide sequences (Hill and Hastie, 1987;Pages et al, 1990), although their amino acid sequences in the conserved region are not identical (Fig. 6).…”