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Iu V Kozlov

Publications and source records attributed to Iu V Kozlov.

At least 19 recordsLinked to original sources
PubMedDate not supplied

[Two forms of precursors of a heparin-binding EGF-like growth factor-diphtheria toxin receptor].

A new mRNA coding for the heparin-binding EGF-like growth factor (HB-EGF) was found in Vero cells. The corresponding cDNA had C-156 in place of T, which resulted in a loss of the NheI site and a substitution of Leu-33 with Pro in the HB-EGF precursor. The known and new forms of the precursor were accordingly termed L and P. A possible conformational change in the corresponding propeptide region were assumed to affect processing of soluble secreted HB-EGF. The L and P mRNAs are differently expressed in various cell lines and have the identical 5'-untranslated sequences. Possibly, they are transcribed from one promoter and then alternatively spliced. Stimulation of resting Vero cells with tetraphorbol ester (TPA) substantially increased production of the L form, decreased production of the P form, and did not affect expression of the total HB-EGF mRNA. This was associated with an increase in binding of the diphtheria toxin, suggesting that the L HB-EGF precursor acts as its receptor.

Amino Acid Sequence↗
PubMedDate not supplied

[A short form of the heparin-binding EGF-like growth factor with a changed EGF domain].

In all secreted proteins related to the epidermal growth factor (EGF), EGF domains that occur in a mature factor are each encoded by two exons, and those that do not, by one exon. During splicing, additional exon 3a can be inserted between exons 3 and 4, which code for the EGF domain of the mature heparin-binding EGF-like growth factor (HB-EGF). The resulting mRNA codes for the short form of HB-EGF (SF HB-EGF), which retains the signal peptide, the propeptide, and the heparin-binding domain. However, its EGF domain lacks the C-terminal subdomain essential for the interaction with the EGF receptor (EGFR). Structural analysis suggested that SF HB-EGF is a secreted polypeptide that has high affinity for heparin, but weakly, if at all, interacts with EGFR. Data obtained in three different systems indicated that SF HB-EGF possesses a mitogenic activity but utilizes a signal transduction pathway other than that of HB-EGF.

Alternative Splicing↗
PubMedDate not supplied

[Ribosome-inactivating lectins from plants].

There is a heterogeneous group of plant proteins which are able to enzymatically inactivate ribosomes by depurination of an invariant adenine from the 28 S ribosomal RNA. Some of these proteins are heterodimers having a lectin subunit which is joined by disulfide bond to the enzymatic subunit. Ricin and abrin which are among the most toxic substances known belong to the last group. This review focuses on the structure of the heterodimeric plant ribosome-inactivating proteins, the way of their action on ribosome, biosynthesis, intracellular trafficking, and their possible usage in medicine.

Abrin↗
PubMedDate not supplied

[The short form of heparin-binding EGF-like growth factor. Part II].

The structure of monkey (Chlorocebus aethiops) heparin-binding EGF-like growth factor (HB-EGF) gene has been investigated in this work in comparison with the known structure of human gene. It was shown that HB-EGF short form (SF-HB-EGF) specific exon 3a is mapped between exons 3 and 4 at distance 700 b.p. from exon 4. In a number of human and simian cell lines the main part of SF-HB-EGF mRNA does not contain HB-EGF mRNA specific exons 4 and 5. In comparison with HB-EGF mRNA in SF-HB-EGF mRNA P-form, but not L-form of is predominant, and this mRNA encodes a polypeptide with changed propeptide structure. Labeled SF-HB-EGF competes with HB-EGF and EGF for binding sites at A431 cell surface, which may be due to interaction with specific receptor. All the data suggest a specific role of SF-HB-EGF in cellular signalization.

Alternative Splicing↗
PubMedDate not supplied

[Primary structure of RNA 3 of barley stripe mosaic virus and its variability].

The complete nucleotide sequence was determined for three variants of the third genomic component of BSMV strain Argentina mild. The common variant, RNA 3 (2797 nucleotide), contains two open reading frames (ORFs) coding for two proteins with Mr of 74,229 (putative BSMV RNA polymerase) and Mr of 16,994. The second ORF is expressed from a subgenomic RNA. The extended variant RNA 3 differs from the common one only by the presence of a direct tandem repeat 351-363 nucleotides in length (with some variability) encompassing part of the leader sequence and the beginning of the first ORF. The resulting protein has a Mr of about 86,000. The defective variant, RNA 4, carries a deletion of 185 nucleotides in the 3'-end proximal part of the first ORF, which shortens the product to a Mr of 60,344.

Amino Acid Sequence↗
PubMedDate not supplied

[Changes in the composition of double-stranded sequences of poly(A)-containing RNA in cell cytoplasm during hormonal induction].

Double-stranded segments (c-ds) have been studied in the poly(A)+ cytoplasmic rat liver RNA. Duplexes about 40 base pairs long have been shown to be of intermolecular character and originate from the interaction between ss-RNA and complementary regions of the poly(A)-containing RNA molecules. Shorter ds-sequences are, mainly, of intramolecular nature. Double-stranded sequences of different length differ also in their oligonucleotide composition, according to fingerprint analysis data. Under the action of cortisone, only several kinds of double-stranded sequences have been demonstrated to increase in the population of cytoplasmic poly(A)+RNA. The function of ds-regions in the hormonal regulation of gene expression is suggested.

Animals↗
PubMedDate not supplied

[Genetic recombination between natural isolates of influenza virus serotypes H1N1 and H3N2].

Oligonucleotide mapping of individual genes was used for search of possible genetic recombinants between natural isolates of influenza H1N1 and H3N2 viruses isolated in the USSR in 1977-1979. No antigenic hybrids and recombinants with the antigenic structure H3N2 were found, however, it was shown that isolates of H1N1 viruses of 1979 (the A/USSR/61/79 strain) might represent genetic recombinants carrying genes P1 + P2 from H3N2 viruses, the M-gene of the USSR/61/79 virus being closest in its structure to the analogous gene of the earliest isolate of H3N2 viruses, namely A/Hong Kong/1/68. Possible selective advantages of virus recombinants having M-genes from viruses of a different serotype are discussed.

Genes, Viral↗
PubMedDate not supplied

[Genetic variability of epidemic strains of influenza virus serotypes H1N1 and H3N2 during antigenic drift].

Data are presented on structural variability of individual genes of selected variants of epidemic influenza viruses H1N1 (1977-1979) and H3N2 (1968-1979) in the course of antigenic drift obtained by oligonucleotide mapping. Six out of 8 genes of H1N1 viruses were found to be more variable than the corresponding genes of H3N2 viruses. Only HA and NS genes of H3N2 viruses underwent greater structural changes as compared with the analogous genes of H1N1 viruses. In viruses of both serotypes, most variable were the genes coding for hemagglutinin and matrix protein. Possible causes of greater structural variability of the matrix protein gene in the course of antigenic drift are discussed.

Antigenic Variation↗