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F Citarella

Publications and source records attributed to F Citarella.

8 recordsLinked to original sources
PubMed1992

Control of human coagulation by recombinant serine proteases. Blood clotting is activated by recombinant factor XII deleted of five regulatory domains.

The availability of engineered serine proteases allows one to study the activation, substrate specificity and regulation of human coagulation and fibrinolytic activities. Human coagulation factor XII is composed of the protease catalytic region at the C-terminus, a hinge proline-rich region and regulatory domains at the N-terminus. From cDNA clones coding for factor XII, two DNA molecules were constructed, one being full length and the other being deleted of exons coding for the regulatory domains. Engineered factor-XII cDNA species were inserted by a homologous recombination technique into vaccinia viruses, which were used to infect the human hepatoma cell line HepG2. Two recombinant proteins were prepared from the culture media and identified by their antigenic properties and electrophoretic mobilities. The recombinant protein of larger size was identified as the full-length factor XII of 80 kDa and its specific activities and activation patterns, determined both by the coagulation and the amidolytic assays, are very similar to these of native human factor XII. The recombinant protein of smaller size was identified as a 319-amino-acid-deleted factor-XII protein of 32 kDa, containing only the entire protease region and part of the proline-rich hinge. This protein was expected to be the 'minimal' portion of factor XII able to sustain protease but unable to recognize substrates and surfaces necessary to activate the contact phase of coagulation. However, this 'minimal' factor-XII protein displays a marked protease activity and, although lacking five regulatory domains of factor XII, is bound and activated by negative charges and promotes coagulation with high efficiency.

Base Sequence↗
PubMed1991

Nucleotide sequence of a DNA region comprising the gene for elongation factor 1 alpha (EF-1 alpha) from the ultrathermophilic archaeote Pyrococcus woesei: phylogenetic implications.

The gene encoding elongation factor 1 alpha (EF-1 alpha, 1290 bp) of the ultrathermophilic, sulfur-reducing archaeote Pyrococcus woesei was localized within a Bg/II fragment of chromosomal DNA. Sequence analysis showed that the EF-1 alpha gene is the upstream unit of a three-gene cluster comprising the genes for ribosomal protein S10 (306 bp) and transfer RNAser (GGA). The three genes follow each other immediately in the order EF-1 alpha.S10.tRNA(ser) after a putative promoter located 55 bp upstream of the EF-1 alpha gene. Alignment of the derived EF-1 alpha sequence with the corresponding sequences from Eukarya, Bacteria/organelles, and with available archaeal sequences (Sulfolobus, Thermococcus, Methanococcus, Halobacterium) showed that Pyrococcus EF-1 alpha is highly homologous (89% identity) to Thermococcus celer EF-1 alpha, both being strikingly more similar to eukaryotic EF-1 alpha than to bacterial EF-Tu. Unrooted dendrograms computed from aligned sequences by distance matrix and DNA parsimony methods, including evolutionary parsimony, showed the Archaea to be a monophyletic-holophyletic cluster closer to Eukarya than to Bacteria. Both distance matrix and DNA parsimony--although not evolutionary parsimony--support the partition of the known archaeal lineages between the kingdoms Crenarchaeota and Euryarchaeota, and the affiliation of the Pyrococcus-Thermococcus lineage to the Euryarchaeota, of which it is the most primitive offspring. A closer relation of Pyrococcus to Euryarchaeota than to Crenarchaeota was also inferred from sequence analysis of S10 ribosomal proteins.

Amino Acid Sequence↗
PubMed1988

Assignment of human coagulation factor XII (fXII) to chromosome 5 by cDNA hybridization to DNA from somatic cell hybrids.

Human coagulation factor XII (fXII), a serine protease synthesized in liver and active in plasma, is involved in a wide variety of functions, including blood coagulation, fibrinolysis, bradykinin and complement activation. A complementary DNA (597 bp) encoding amino acid -16 to amino acid 183 of fXII protein was used to determine the chromosomal location of the fXII gene. DNAs from hamster-human somatic cell hybrids were digested with restriction enzymes and hybridized with the fXII cDNA. By the Southern method it was shown that restriction fragments able to hybridize to fXII cDNA are present only in DNA extracted from clones retaining human chromosome 5.

Animals↗
PubMed1986

Hypothalamic-pituitary-ovarian axis in women with operable breast cancer treated with adjuvant CMF and tamoxifen.

The effect of adjuvant CMF (cyclophosphamide, methotrexate, and 5-fluorouracil) and tamoxifen (TM) on hypothalamic-pituitary-ovarian function was studied in 120 women with stage I-II operable breast cancer. Sixty patients were premenopausal, of whom 25 were treated with CMF for 9 cycles, 25 with CMF for 9 cycles + TM for 2 years, started concurrently, and 10 with TM alone for 2 years. Sixty patients were postmenopausal and they were all treated with TM alone for 2 years. In all groups treatment was started within 4 weeks of mastectomy. Plasma levels of estrone (E1), estradiol-17 beta (E2), follicle-stimulating hormone, luteinizing hormone (LH), prolactin (Prl), testosterone (T) and thyroid-stimulating hormone (TSH) were determined in all patients before surgery and again at 3-month intervals from initiation of the adjuvant therapy. In ten patients of each treatment group FSH-LH and Prl-TSH release was determined following stimulation with releasing hormones. CMF and CMF+TM therapy resulted in amenorrhea in 42/50 premenopausal patients with decrease of E1+E2 (p less than 0.001) and elevation of FSH (p less than 0.001) and LH (p less than 0.01) plasma concentration to postmenopausal levels. In premenopausal women treated with TM a marked increase of E1+E2 (p less than 0.001) was observed with unaltered FSH-LH plasma concentration. A significant fall of Prl also occurred in these patients. In postmenopausal women and premenopausal patients with CMF-induced amenorrhea TM produced a marked fall of FSH-LH and a decrease of Prl plasma level. Plasma TSH and T were not affected in any patient by any of the treatment regimens. The results of the stimulatory tests are in agreement with the hormonal changes observed under basal conditions and indicate that, whereas CMF suppresses the ovary and does not alter hypothalamic-pituitary function, TM induces profound changes of the hypothalamic-pituitary-ovarian axis.

Adult↗
PubMed1986

Role of arachidonate metabolism on the in vitro release of luteinizing hormone and prolactin from the anterior pituitary gland: possible involvement of lipoxygenase pathway.

The aim of the present study was to evaluate whether arachidonic acid metabolism may play a role on luteinizing hormone (LH) and prolactin (PRL) release directly at the pituitary level. To this purpose, exogenous arachidonic acid, alone or in presence of inhibitors of cyclooxygenase (indomethacin:IND) and lipoxygenase pathways (nordihydroguaiaretic acid:NDGA), was added to perfused rat anterior pituitary cells. PGE, PGF alpha, LH and PRL levels present in the eluate were assayed with specific RIA methods. Both PGE and PGF alpha show a dose-related response after the addition of increasing doses of arachidonic acid. The addition of 0.05 mM arachidonic acid induces an increase of LH and PRL. The addition of IND to the perfusion medium highly potentiates the stimulatory effects induced by arachidonic acid on LH and PRL release. On the contrary, the addition to the medium of either NDGA or IND plus NDGA completely reverses the stimulatory action induced by arachidonic acid alone. The present results suggest that: adenohypophyseal cells are able to metabolize exogenous arachidonic acid; arachidonic acid induces an elevation in LH and PRL levels; lipoxygenase pathway metabolite(s) are likely involved in these activities, and the site of action of arachidonic acid is at the pituitary level.

Animals↗