An artificial protein,possessing biological activity of HL-60 human promyelocytic leukemia differentiation factor

The ABB-df artificial protein was prepared by inserting the TGENHR biologically active peptide corresponding to the 41-46 sequence of the differentiation factor for the HL-60 cell line of the human promyelocyte leukemia into the N-terminus of the polypeptide chain of albebetin, an artificial protein with the preset structure. The ABB-df protein was found to induce the differentiation of HL-60 cells and to inhibit their proliferation; its efficiency was almost the same as that of the starting peptide. According to CD spectroscopy, the inclusion of the peptide fragment into albebetin exerts virtually no effect on the regular secondary structure of albebetin.     

The Impact of Power on Humanity: Self-Dehumanization in Powerlessness

Power gives people the ability to control themselves and their environment, and this control is considered a fundamental human need. We investigated whether experiencing powerlessness induces the experience of self-dehumanization using three methods: priming, role-playing, and cueing. People in a position of low power viewed themselves (Experiments 1–3) as less human relative to people in a position of high power; furthermore, people with low power believed that they were viewed as less human by others as well (Experiments 2–3). In all of the experiments, human nature traits were most negatively affected by powerlessness in self-perception judgments, and uniquely human traits were most negatively affected by powerlessness in meta-perception judgments. Furthermore, the powerless believed they were viewed as less human not only by the powerful people but also the outside observers of the power dynamic. Self-dehumanization also appears to be a consequence of powerlessness rather than an incidental result of a change in mood or a negative self-view. Our findings are an important extension of previous work on the adverse effects of powerlessness and dehumanization.     

The Precursor of Differentiation Factor HLDF and Ribosomal Protein RPS21 Have a Common N-Terminal Sequence

The mature differentiation factor HLDF, isolated from cultural medium, comprises 54 aa, whereas the open reading frame of mRNA encodes a 97-aa protein. We presumed that the protein translation begins from the first ATG codon, whose environment mostly meets the requirements for the initiation point. Two more ATG triplets are localized in positions 48–50 and 100–102 (numbering according to the structure of S21), i.e., in the area preceding the cDNA fragment that encodes the N-terminal fragment of the mature protein. The mRNAs of HLDF and S21 ribosomal protein have previously been shown to be highly homologous, and, therefore, their differences appear to be derived from two point deletions in the cDNA of the HLDF-encoding sequence (a G residue in position 112 and a C residue in position 224). As a result, the mature differentiation factor and RPS21 may be the products of translation from different open reading frames, the differentiation factor may be synthesized in the cell as a precursor, and its N-terminal sequence may be identical to that of RPS21. To test this hypothesis, we prepared recombinant RPS21 and the polyclonal antibodies to HLDF, full-size RPS21, and the C-terminal RPS21 peptide. Immunochemical staining by specially produced antibodies of native HL-60 cells and the same cells brought into apoptosis or differentiation confirmed that the precursor of the differentiation factor and the ribosomal S21 protein have a common N-terminal sequence and different cellular localizations. Neither an intron-containing gene nor a pseudogene with the nucleotide sequence corresponding to the HLDF cDNA was detected in the human genome or in the HL-60 cell line genome. On the basis of these facts, we propose a hypothesis of the molecular mechanism of the HLDF mRNA biosynthesis by means of posttranslational modifications of pre-mRNA of RPS21.     

Relationship of neural cell adhesion molecules (N-CAMs) with adenylate cyclase.

Bovine brain cDNA cloned earlier and attributed to calmodulin-independent adenylate cyclase encodes the neural cell adhesion molecule (N-CAM). The expression of N-CAM mRNA in Xenopus laevis oocytes increases their basal adenylate cyclase activity. Polyclonal antibodies against synthetic peptide A, VAENQQGKSKAAHFV (664-678 amino acid residues of bovine N-CAM), containing sequence AXXXXGKS which is homologous to the nucleotide-binding consensus sequence GXXXXGKS, inhibit the adenylate cyclase activity. A close relationship appears to exist between adenylate cyclase and N-CAM.     

Selection of DNA aptamers specifically interacting with the fibrillar form of the yeast Sup35 protein

Single-stranded DNA aptamers interacting with fibrils of Saccharomyces cerevisiae Sup35p were obtained by the SELEX procedure. The specificity of interactions with Sup35p was investigated for 10 out of 40 selected aptamers. Nine aptamers were found to bind to the fibrillar but not to the monomeric form of Sup35p. The dissociation constant of the aptamer-fibril complex ranged from 0.1 to 1.0 μM for different aptamers. The aptamers can be used to study the prion transformation of Sup35p.