346 research outputs found
Alternative Shaker transcripts express either rapidly inactivating or noninactivating K+ channels.
A study of the regions of ribosomal proteins S4, S8, S15 and S20 that interact with 16 S RNA of Escherichia coli
Molecular basis of altered excitability in Shaker mutants of Drosophila melanogaster.
Mutations in the Shaker (Sh) locus of Drosophila melanogaster have differing effects on action potential duration and repolarization in neurons as well as on A-type K+ channels (I(A)) in muscle. The molecular basis of three exemplary Sh alleles (Sh(KS133), Sh(E62) and Sh5) has been identified. They are point mutation in the Sh transcription unit expressing aberrant voltage-gated A-type K+ channels. Replicas of each mutation have been introduced by in vitro mutagenesis into Sh cDNA. The expression of in vitro transcribed mutant Sh cRNA in Xenopus laevis oocytes reproduced the specific phenotypic traits of each Sh allele. The lack of I(A) in Sh(KS133) is due to a missense mutation within a sequence motif occurring in all hitherto characterized voltage-gated K+ channel forming proteins. The reduction of I(A) in Sh(E62) is due to a mutation in an AG acceptor site. The intervening sequence between exon 19 and 20 is not spliced in Sh(E62) RNA. As a consequence Sh(E62) flies do not contain the full complement of Sh K+ forming proteins. Finally, the Sh5 mutation leads to an altered voltage dependence of K+ channel activation and inactivation as well as to an accelerated rate of recovery from inactivation. This is due to a missense mutation altering the amino acid sequence of the proposed transmembrane segment S5 of the Sh K+ channels. Segment S5 is located adjacently to the presumed voltage sensor of voltage-gated ion channels. The results explain the altered properties of excitable cells in Sh mutants and provide a general model for the possible role of A-type K+ channels in modulation action potential profiles
ΠΡΠ΅Π΄ΠΎΠΏΡΡ ΠΎΠ»Π΅Π²Π°Ρ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΠΈΡ ΠΌΠΎΠ»ΠΎΡΠ½ΡΡ ΠΆΠ΅Π»Π΅Π· Π² ΡΠ°Π·Π»ΠΈΡΠ½ΡΡ ΡΡΠ½ΠΈΡΠ΅ΡΠΊΠΈΡ ΠΏΠΎΠΏΡΠ»ΡΡΠΈΡΡ Π½Π°ΡΠ΅Π»Π΅Π½ΠΈΡ ΠΡΡΠΌΠ°
Π‘Π΅ΡΠ΅Π΄ ΠΆΡΠ½ΠΎΡΠΎΠ³ΠΎ Π½Π°ΡΠ΅Π»Π΅Π½Π½Ρ ΠΠ Π Π²ΠΈΡΠ²Π»Π΅Π½Ρ ΠΏΠΎΠΏΡΠ»ΡΡΡΡ ΡΠ· ΡΠΊΡΠ°ΠΉ Π²ΠΈΡΠΎΠΊΠΎΡ
Π·Π°Ρ
Π²ΠΎΡΡΠ²Π°Π½ΡΡΡΡ Π ΠΠ (Π°ΡΠΌΡΠ½ΠΊΠΈ - 114,25); Π· Π²ΠΈΡΠΎΠΊΠΎΡ Π·Π°Ρ
Π²ΠΎΡΡΠ²Π°Π½ΡΡΡΡ (ΡΠ»ΠΎΠ²βΡΠ½ΠΊΠΈ -
65,21); Π° ΡΠ°ΠΊΠΎΠΆ Π· Π²ΡΠ΄Π½ΠΎΡΠ½ΠΎ Π½ΠΈΠ·ΡΠΊΠΎΡ Π·Π°Ρ
Π²ΠΎΡΡΠ²Π°Π½ΡΡΡΡ (ΠΊΡΠΈΠΌΡΡΠΊΡ ΡΠ°ΡΠ°ΡΠΊΠΈ - 41,99 Π½Π°
100 ΡΠΈΡ. Π²ΡΠ΄ΠΏΠΎΠ²ΡΠ΄Π½ΠΎΠ³ΠΎ ΠΆΡΠ½ΠΎΡΠΎΠ³ΠΎ Π½Π°ΡΠ΅Π»Π΅Π½Π½Ρ; Ρ < 0,001). ΠΠΎΡΡΠ²Π½ΡΠ»ΡΠ½ΠΈΠΉ Π°Π½Π°Π»ΡΠ·
ΠΏΠΎΡΠΈΡΠ΅Π½ΠΎΡΡΡ Π΄ΠΎΠ±ΡΠΎΡΠΊΡΡΠ½ΠΎΡ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΡΡ Π² 531 ΠΏΠ°ΡΡΡΠ½ΡΠΊΠΈ (399 ΡΠ»ΠΎΠ²βΡΠ½ΠΎΠΊ, 69 ΡΠ°ΡΠ°ΡΠΎΠΊ, 63
Π°ΡΠΌΡΠ½ΠΊΠΈ) ΠΏΠΎΠΊΠ°Π·Π°Π², ΡΠΎ Π²ΡΡΠΎΠ³ΡΠ΄Π½ΠΎ Π½Π°ΠΉΠ±ΡΠ»ΡΡ ΡΠ°ΡΡΠΈΠΌΠΈ Π·Π°Ρ
Π²ΠΎΡΡΠ²Π°Π½Π½ΡΠΌΠΈ Ρ Π²ΡΡΠΌΠ΅Π½ΡΡΠΊΡΠΉ
ΠΏΠΎΠΏΡΠ»ΡΡΡΡ Π· Π²ΠΈΡΠΎΠΊΠΎΡ Π·Π°Ρ
Π²ΠΎΡΡΠ²Π°Π½ΡΡΡΡ Π ΠΠ Ρ ΠΊΠΈΡΡΡ ΠΌΠΎΠ»ΠΎΡΠ½ΠΈΡ
Π·Π°Π»ΠΎΠ· (Π =0,033) Ρ
Π²ΡΠ·Π»ΠΎΠ²Π° ΡΠΎΡΠΌΠ° ΡΠΈΠ±ΡΠΎΠ·Π½ΠΎ-ΠΊΠΈΡΡΠΎΠ·Π½ΠΎΠΉ Ρ
Π²ΠΎΡΠΎΠ±ΠΈ (Π =0,040), ΡΠΊΡ, ΠΎΡΠ΅Π²ΠΈΠ΄Π½ΠΎ, ΠΌΠΎΠΆΠ½Π°
Π²ΡΠ΄Π½ΠΎΡΠΈΡΠΈ Π΄ΠΎ ΠΏΡΠ΅Π΄ΡΠ°ΠΊΠΎΠ²ΠΎΠΉ ΠΏΠ°ΡΠΎΠ»ΠΎΠ³ΡΡ.In Crimean woman there are populations with very high Breast Cancer incidence (Armenians - 114,25); with high incidence (Slavs - 65,21); and with lowest incidence (Tatars - 41,99 in 100 000 woman populations; Ρ < 0,001). In 531 patients (399 Slavs, 69 Tatars, 63 Armenians) more freqwently was diagnosed Breast Cysts (Π =0,033) and Nodular Fibrocystic disease (Π =0,040) in Armenian ethnic group with very high Breast Cancer incidence. Breast Cysts and Nodular Fibrocystic disease only are precancerous diseases of the Breast
Active sites in Escherichia coli ribosomes
AbstractIn the figure, 30 S ribosomal proteins have been arranged according to their functional role: Protein S1 is required for mRNA binding. Proteins S3, S4, S5, S11 and S12 are involved in cistron and/or codonβanticodon recognition. They must be close to the decoding sites on the 30 S subunit. Furthermore proteins S2, S3, S10, S14, S19 and S21 function in f-Met-tRNA binding. Proteins S1, S2, S3, S10, S14, S19, S20 and S21 are important for the function of both decoding sites, whereas proteins S9, S11 and S18 are only needed for EFβTu-dependent aminoacyl-tRNA binding. Proteins S2, S5, S9 and S11 would be close to the GTPase center of the 50 S subunit, since they are important for this activity.The present available data concerning the 50 S subunit allow the following picture to be drawn: Protein L16 is involved in binding the 3β²-terminus of aminoacyl-tRNA in the A-site. Next to it in the A-site, there is protein L6. The P-site is located adjacent to the A-site of the peptidyltransferase center. Accordingly, protein L2 is near protein L6 and is located in the P-site as well as proteins L27 and L4. Protein L11, which is intimately involved in peptide bond formation, would have to border parts of both A- and P-sites. Proteins L6 and L2 stimulate binding of 5 S RNAβprotein complexes to 23 S RNA. The 5 S RNAβprotein complex has GTPase and ATPase activities. The proteins in this complex (L5, L18, L20, L25 and L30) seem to be located close to the A-site of the peptidyltransferase center. These proteins together with protein L11 are involved in GDP binding. Proteins L10 and L6 are implicated in reconstitution of protein L7 and L12 mediated EFβG-dependent ribosomal GTP hydrolysis. This observation is supported by the fact that the aminoacyl-tRNA binding site, e.g. proteins L16 and L6, is connected with EFβG and EFβTu binding site, e.g. proteins L7 and L12, as well as the GTPase center. Furthermore, if one of the functional roles of 5 S RNA is to bind aminoacyl-tRNA via TβΞ¨βC, then those ribosomal proteins which bind to 5 S RNA (or are close to it) would be located near or at the A-site.The model of active sites in E. coli ribosome illustrated in the figure is based on the presently available experimental results. It is far from being complete and should not be overinterpreted as an accurate topographical model. More data on the functional role of ribosomal components and on the topography of the subunits can be expected in the near future and will add to the knowledge on the active sites in ribosomes
Π Π΅ΡΡΡΡΠΊΡΡΡΠΈΠ·Π°ΡΠΈΡ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΡ (Π½Π° ΠΏΡΠΈΠΌΠ΅ΡΠ΅ ΠΠΠ Β«ΠΠ΅ΡΠ΅Π΄Π²ΠΈΠΆΠ½Π°Ρ ΠΌΠ΅Ρ Π°Π½ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½Π°Ρ ΠΊΠΎΠ»ΠΎΠ½Π½Π°-Π’ΠΎΠΌΡΒ»)
Π ΠΏΡΠΎΡΠ΅ΡΡΠ΅ ΠΈΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½ΠΈΡ ΠΎΠΏΡΠ΅Π΄Π΅Π»Π΅Π½ΠΎ ΡΠΊΠΎΠ½ΠΎΠΌΠΈΡΠ΅ΡΠΊΠΎΠ΅ ΡΠΎΠ΄Π΅ΡΠΆΠ°Π½ΠΈΠ΅ ΠΏΡΠΎΡΠ΅ΡΡΠ° ΡΠ΅ΡΡΡΡΠΊΡΡΡΠΈΠ·Π°ΡΠΈΠΈ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΡ; ΠΏΡΠ΅Π΄ΡΡΠ°Π²Π»Π΅Π½ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΌ ΡΠ΅Π°Π»ΠΈΠ·Π°ΡΠΈΠΈ ΡΠ΅ΡΡΡΡΠΊΡΡΡΠΈΠ·Π°ΡΠΈΠΈ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΉ; ΠΎΡ
Π°ΡΠ°ΠΊΡΠ΅ΡΠΈΠ·ΠΎΠ²Π°Π½Ρ ΠΎΡΠ½ΠΎΠ²Π½ΡΠ΅ ΠΌΠ΅ΡΠΎΠ΄Ρ ΠΎΡΠ΅Π½ΠΊΠΈ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ ΠΏΡΠΎΡΠ΅ΡΡΠ° ΡΠ΅ΡΡΡΡΠΊΡΡΡΠΈΠ·Π°ΡΠΈΠΈ ΠΏΡΠ΅Π΄ΠΏΡΠΈΡΡΠΈΠΉ; ΠΏΡΠΎΠ²ΠΎΠ΄ΠΈΠ»Π°ΡΡ ΠΎΡΠ΅Π½ΠΊΠ° ΡΠΈΠ½Π°Π½ΡΠΎΠ²ΠΎΠ³ΠΎ ΡΠΎΡΡΠΎΡΠ½ΠΈΡ ΠΠΠ Β«ΠΠ΅ΡΠ΅Π΄Π²ΠΈΠΆΠ½Π°Ρ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½Π°Ρ ΠΊΠΎΠ»ΠΎΠ½Π° β Π’ΠΎΠΌΡΒ»; ΠΏΡΠ΅Π΄Π»ΠΎΠΆΠ΅Π½ ΠΏΠ»Π°Π½ ΡΠ΅ΡΡΡΡΠΊΡΡΡΠΈΠ·Π°ΡΠΈΠΈ ΠΠΠ Β«ΠΠ΅ΡΠ΅Π΄Π²ΠΈΠΆΠ½Π°Ρ ΠΌΠ΅Ρ
Π°Π½ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Π½Π°Ρ ΠΊΠΎΠ»ΠΎΠ½Π° β Π’ΠΎΠΌΡΒ» Ρ ΠΎΡΠ΅Π½ΠΊΠΎΠΉ Π΅Π³ΠΎ ΡΡΡΠ΅ΠΊΡΠΈΠ²Π½ΠΎΡΡΠΈ.The study defined economic content of the enterprise restructuring process; The mechanism of the implementation of the restructuring of enterprises; It describes the main methods for evaluating the effectiveness of the process of restructuring enterprises; evaluated the financial condition of Limited Liability Company Β«PMK β Tom'Β»; proposed restructuring plan of Limited Liability Company Β«PMK β Tom'Β» with the evaluation of its effectiveness
ΠΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠΉ ΡΡΡΡΠΊΡΡΡΠ½ΡΠΉ ΡΠ°ΠΊΡΠΎΡ Π΄Π»Ρ ΠΏΠ»ΠΎΡΠ½ΠΎΠΉ ΠΊΠ²Π°Π·ΠΈΠΊΠ»Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΡ
ΠΡΡΠ»Π΅Π΄ΠΎΠ²Π°Π½Ρ ΠΈ ΠΏΡΠΎΠ°Π½Π°Π»ΠΈΠ·ΠΈΡΠΎΠ²Π°Π½Ρ Π΄ΠΈΠ½Π°ΠΌΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΡΡΡΠΊΡΡΡΠ½ΡΠ΅ ΡΠ°ΠΊΡΠΎΡΡ Π΄Π»Ρ ΠΏΠ»ΠΎΡΠ½ΠΎΠΉ ΠΊΠ²Π°Π·ΠΈΠΊΠ»Π°ΡΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΏΠ»Π°Π·ΠΌΡ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΏΡΠ΅Π²Π΄ΠΎΠΏΠΎΡΠ΅Π½ΡΠΈΠ°Π»Π°, ΡΡΠΈΡΡΠ²Π°ΡΡΠ΅Π³ΠΎ ΡΡΡΠ΅ΠΊΡ Π΄ΠΈΡΡΠ°ΠΊΡΠΈΠΈ ΠΈ ΠΊΠΎΠ»Π»Π΅ΠΊΡΠΈΠ²Π½ΡΠ΅ ΡΡΡΠ΅ΠΊΡΡ Π² ΡΠΈΡΠΎΠΊΠΎΠΌ Π΄ΠΈΠ°ΠΏΠ°Π·ΠΎΠ½Π΅ ΡΠ΅ΠΌΠΏΠ΅ΡΠ°ΡΡΡ.The dynamical structure factor for dense semiclassical plasma, which takes into account the diffraction effect in a wide range of densities and temperatures was investigated
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