Disease relevance of TF

• Delayed hypersensitivity (DH) and protective immunity were transferred to nonimmune 4- and 10-week-old broiler chickens with transfer factor (TF) prepared from splenic leukocytes of chickens immunized with CocciVac D [1].
• The open reading frames from these cDNAs predict a 738 amino acid protein with homology to human melanotransferrin, a membrane-found, transferrin-like protein that is expressed at high levels by a subset of melanomas, tumor cell lines, fetal intestine, and liver, but not by most normal adult tissues [2].
• The interference with Ag presentation induced by Listeria was found for a second Ag (conalbumin) [3].
• We observed no effect of these hormones on the ability of E. coli RNA polymerase to transcribe specifically the conalbumin and ovalbumin genes 8 1/2 h after hormone administration when transcription of these genes by endogenous RNA polymerase was elevated 5- and 30-fold, respectively [4].
• Diaphyseal chondrocyte maturation was indeed delayed in squalamine-treated humeri, as indicated by reduced cell hypertrophy and expression of type X collagen, transferrin, and Indian hedgehog (Ihh) [5].

High impact information on TF

• Sequence homologies with this 5'-upstream region were observed in other fragments of the ovalbumin, conalbumin, ovomucoid, X and Y genes, which were also efficient competitors [6].
• Sequence comparison at the 5' end of the lysozyme, conalbumin and ovalbumin genes reveals only one region of partial homology, 140 nucleotides upstream from the mRNA start sites [7].
• In contrast, transcription from the conalbumin gene is fully induced by estrogen in the presence or absence of peptide factors or serum, despite the fact that these two egg white genes are both transcribed in the same cells in response to the same steroid hormones [8].
• The nucleotide sequence of the cloned transforming gene suggests that it encodes a protein that is partially homologous to the amino terminus of transferrin and related proteins although only about one tenth the size of transferrin [9].
• The conalbumin gene has been cloned and shown to consist of at least 17 exons approximately 60-200 base pairs long [10].

Biological context of TF

• Change in glycosylation of chicken transferrin glycans biosynthesized during embryogenesis and primary culture of embryo hepatocytes [11].
• Moreover, comparative analysis of chicken serum transferrin and ovotransferrin glycans reinforces the idea that the glycosylation of two identical polypeptide chains is organ specific [11].
• High and low frequency repetitive sequences are found both upstream from the conalbumin gene and within one intron [10].
• The nucleotide sequence of an almost double-stranded cDNA copy [Cochet, M., Perrin, F., Gannon, F., Krust, A., Chambon, P., McKnight, G. S., Lee, D. C., Mayo, K. E., and Palmiter, R. D. (1979) Nucleic Acids Res. 6, 2435-2452] of chicken ovotransferrin (conalbumin) mRNA has been determined [12].
• Transcription factors (TFs) are essential regulators of gene expression, and mutated TF genes have been shown to cause numerous human genetic diseases [13].

Anatomical context of TF

• Conalbumin, when synthesized in a rabbit reticulocyte cell-free translation system, was found to contain an NH2-terminal extension of 19 amino acid residues [14].
• The effects of TF on T-lymphocyte mediated protective immunity to coccidia in chickens are discussed [1].
• Only chickens injected with the immune TF showed DH by wattle reaction to oocyst antigen and protective immunity to Eimeria tenella challenge infection [1].
• The short chain aliphatic acid salts, butyrate and propionate, are effective inhibitors of histone deacetylation in chick oviduct at 2--5 mM; they also prevent the hormonal induction of the ovalbumin and transferrin genes [15].
• We show that the microinjected ovalbumin and conalbumin promoter regions do not function in chicken fibroblasts, kidney cells and in a variety of non-chicken cells, irrespective of the presence of steroid hormone receptors [16].

Associations of TF with chemical compounds

• The glycan structure of the transferrin secreted by the embryo hepatocytes in primary culture was marked by the presence of fucose (alpha 1-6) linked to the core N-acetylglucosamine, suggesting that expression of the fucosyltransferase activity is dependent on cell culture conditions [11].
• In particular, the embryo serum transferrin glycan differed from that of chicken serum transferrin by the presence of a bisecting N-acetylglucosamine, suggesting a developmental change in glycosylation [11].
• In the structure, both empty iron binding clefts are in the open conformation, lending weight to the theory that Fe(3+) binding or release in transferrin proceeds via a mechanism that involves domain opening and closure [17].
• The overall structure of ovotransferrin is similar to those of human lactoferrin and rabbit serum transferrin, being folded into two homologous lobes, each containing two dissimilar domains with one Fe3+ and one CO3(2)- bound at a specific site in each interdomain cleft [18].
• Structural evidence for a pH-sensitive dilysine trigger in the hen ovotransferrin N-lobe: implications for transferrin iron release [19].

Physical interactions of TF

• Butyrylcholinesterase is complexed with transferrin in chicken serum [20].
• Interaction of eukaryotic class-B transcription factors and chick progesterone-receptor complex with conalbumin promoter sequences [21].

Co-localisations of TF

• Partially purified neurotrophic factor (NTF) from chicken nerves comigrated with transferrin and a component in several preparations known to have neurotrophic effects on cultured skeletal muscle cells [22].

Other interactions of TF

• CVG cells were explanted from chick embryos after 90 h of incubation into a defined-medium containing BDNF, NT-3, or NT-4/5 and an insulin, transferrin, selenium, and progesterone supplement [23].
• Conalbumin mRNA begins to accumulate within 30 min after estrogen administration, whereas there is a lag of approximately 3 hr before ovalbumin mRNA begins to accumulate, as measured by three independent assays [24].
• The embryo synthesizes every plasma protein including fetoproteins and "adult" proteins (prealbumin, albumin, and transferrin) [25].
• Whereas virtually all aspects of hemopexin, transferrin and albumin production in these cells corresponded to those of cultured primary hepatocytes, fibrinogen was not secreted [26].
• Characterization of early and late endocytic compartments of the transferrin cycle. Transferrin receptor antibody blocks erythroid differentiation by trapping the receptor in the early endosome [27].

Analytical, diagnostic and therapeutic context of TF

• Results indicate that DLE prepared from chickens contain transfer factor (TF) responsible for adoptive transfer of DWR to tuberculin, DT, and KLH [28].
• Most of the controls exerted on the ovalbumin and conalbumin promoters in the whole animal appear to be reproduced in vitro by nuclear microinjection of the chimeric genes into the primary cultured cells [16].
• When thermal denaturation of conalbumin solutions partially saturated with Fe(III) is observed by differential scanning calorimetry, four endotherms are observed between 40 and 100 degrees [29].
• Restriction enzyme mapping of chicken genomic DNA reveals that the conalbumin gene is split and is contained in three EcoRI fragments "a", "b", "b" and "c" which have sizes of 10.7, 4 and 2.5 kb, respectively [30].
• The fragments Eco "b", Eco "c" and part of Eco "a" have been isolated by molecular cloning from three different "libraries". Electron microscopic studies of hybrids between cloned DNA's and conalbumin mRNA show that one of the isolated clones, lambda C4-conl, contains the coding sequences for the first 940 nucleotides of the mRNA (out of 2400) [30].

References