Search PubMed⌕ Search

Biomedical subjects

M Kozak

Publications and source records attributed to M Kozak.

98 records · Page 6Linked to original sources
PubMed1975

RNA synthesis in cells infected with herpes simplex virus. IX. Evidence for accumulation of abundant symmetric transcripts in nuclei.

RNA extracted from nuclei of 8-h infected cells drove approximately 50% of herpes virus DNA into DNA-RNA hybrid. The same RNA, preannealed under conditions which allowed base pairing to take place, drove only 35% of the DNA into DNA-RNA hybrid; further annealing of the RNA did not diminish the amount of RNA sequences remaining available for subsequent hybridization with DNA. Upon denaturation of the preannealed RNA, the RNA sequences sequestered during preannealing became available again for hybridization with DNA. The base pairing that occurred during preincubation of the RNA was inter-molecular, since it was RNA concentration dependent and was not affected by limited alkaline hydrolysis. The nuclear viral transcripts that remained available for hybridization, after preannealing of the RNA, were subset of the RNA sequences that accumulated in the cytoplasm of infected cells. In addition, a small amount (derived from 5% or less of the viral DNA) of complementary transcripts was detected in the cytoplasm.

Base Sequence↗
PubMed1974

Regulation of herpesvirus macromolecular synthesis: nuclear retention of nontranslated viral RNA sequences.

We report two instances of selective accumulation of herpes simplex 1 RNA transcripts in different compartments of infected HEp-2 cells. In the first, transcripts derived from about 50% of the viral DNA accumulated in the nuclei of cells 8 hr after infection. However, only 40-42% of the DNA was represented in transcripts accumulating in both cytoplasm and polyribosomes. A more striking disparity in the distribution of transcripts between nuclei and cytoplasm occurred when viral infection was initiated and maintained for several hours in the absence of protein synthesis. RNA complementary to about 50% of the viral DNA accumulated in the nuclei, while transcripts derived from only about 10% of the DNA were detectable in the cytoplasm. The transcripts that were selectively transported in the presence of cycloheximide seem to be functional messenger RNA molecules, since they were found on polysomes immediately after cycloheximide reversal. In contrast, RNA retained in the nuclei during the period of cycloheximide treatment was not mobilized when protein synthesis subsequently resumed. The two instances of selective RNA transport observed during herpesvirus infection suggest that only viral transcripts competent to function in translation are exported from the nucleus.

Base Sequence↗
PubMedDate not supplied

Point mutations close to the AUG initiator codon affect the efficiency of translation of rat preproinsulin in vivo.

To determine whether sequence context influences the ability of an AUG triplet to be recognized as an initiator codon by eukaryotic ribosomes, single nucleotide changes were introduced near the translational start site in a cloned preproinsulin gene. Maximum synthesis of preproinsulin occurred when a purine, preferably adenosine, was located three nucleotides upstream from the initiator codon. Adenosine is found most frequently in that position in natural mRNAs.

Base Sequence↗
PubMedDate not supplied

[Social perception of AIDS risk].

An all-Polish study was carried out of a representative sample of 1402 adult subjects for establishing the level of social knowledge of AIDS, the character of attitudes, the consequences of informative activities etc. The AIDS threat was considered by the responders as low, with subjects with rather more loose sexual life fearing infection relatively less. It may be supposed that this was due to a greater experience with infections, better knowledge and lower threat awareness. The lack of threat awareness of the society seems to be determined in an equal degree by the low knowledge of AIDS and relatively small number of cases in this country. This limited knowledge of AIDS may lead to a more rapid spread of the disease, and, consequently, to panic reactions, intolerance and aggression against patients and risk groups. This could be prevented only by appropriate health education.

Acquired Immunodeficiency Syndrome↗