Biological activities of human interferon and 2'-5' oligoadenylates in plants.

Exogenous human interferon 2 (IFN) and 2'-5' oligoadenylates (2-5A) have been shown to cause at least a dual physiological effect in tobacco and wheat: (i) increased cytokinin activity and (ii) induced synthesis of numerous proteins, among which members of two groups of stress proteins have been identified, namely pathogenesis-related (PR) and heat shock (HS) proteins. These effects were observed only by low concentrations of these substances: IFN at 0.1-1 u/ml and 2-5A at 1-10 nM.

[Nonribosomal ribonucleoprotein particles in preparations of nonhistone proteins extracted from pigeon erythroblast chromatin]. / Ribonukleoproteidnye chastitsy neribosommoi prirody v ekstraktakh iz khromatina eritroblastov golubei soderzhashchikh negistonovye belki.

Two proteins were isolated from preparations of weakly bound nonhistone proteins, obtained from highly purified chromatin with 0.35 M NaCl. These two protein residues from chromatin RNP-particles have the buoyant density of 1.41 g/cm3 as shown by centrifugation in CsCl gradients and contain heterogeneous fast labelling nuclear RNA. According to SDS polyacrylamide gel electrophoresis the molecular weights of these proteins are 70000 and 43000 daltons.

[Comparative investigation of the non-histone proteins of chromatin from pigeon erythroblasts and erythrocytes]. / Sravintel'noe izuchenie negistonovykh belkov khromatina eritroblastov i eritrotsitov golubia.

Chromosomal non-histone proteins are obtained from nuclei of two types of pigeon erythroid cells: erythroblasts (cells active in RNA synthesis) and erythrocytes (cells with repressed RNA synthesis). They are well soluble in solutions of low ionic strength. Electrophoretic separation of the obtained non-histone proteins in polyacrylamide gels with urea and SDS shows the presence of qualitative differences in the pattern of non-histone proteins of chromatine from erythroblasts and erythrocytes. By electrophoresis in urea some protein bands of non-histone proteins of chromatine from erythroblasts were found which disappear with the aging of cells. At the same time two protein fractions were observed in chromatine from erythrocytes which were absent in that of erythroblasts. Disappearance of some high molecular weight protein fractions from erythrocyte chromatine as compared to erythroblasts was observed by separation of the non-histone proteins in the presence of SDS. These fractions of the non-histone proteins disappearing during aging of cells are well extractable from erythroblast chromatine by 0.35 M NaCl solution. In the in vitro system with E. coli RNA polymerase addition of non-histone proteins of chromatine from erythroblasts to chromatine from erythrocytes increases RNA synthesis 2--3 times. At the same time addition of non-histone proteins from erythrocytes is either without any influence on this process or somewhat inhibiting.