Translational activity

Carter L E and Carter E A1996 Ab initio-derived dynamics for Fj reactions with partially fluorinated Si(IOO) surfaces translational activation as a possible etching tool J. Phys. Chem. 100 873-87... 

The operational model allows simulation of cellular response from receptor activation. In some cases, there may be cooperative effects in the stimulus-response cascades translating activation of receptor to tissue response. This can cause the resulting concentration-response curve to have a Hill coefficient different from unity. In general, there is a standard method for doing this namely, reexpressing the receptor occupancy and/or activation expression (defined by the particular molecular model of receptor function) in terms of the operational model with Hill coefficient not equal to unity. The operational model utilizes the concentration of response-producing receptor as the substrate for a Michaelis-Menten type of reaction, given as... 

A wheat germ, cell-free, translation extract was fractionated into three concentrated parts using ammonium sulfate the 0 - 40 % saturated fraction, the 40 - 60 % saturated fraction, and the ribosome fraction. These fractions were tested for their ability to enhance the translational activity of the wheat germ, cell-free extract for dihydrofolate reductase. The fortified cell-free system supplemented with the 0 - 40 % ammonium sulfate fraction enhanced the efficiency of protein synthesis by 50 %. 

Tzamarias, D., Roussou, I., and Thireos, G. (1989). Coupling of GCN4 mRNA translational activation with decreased rates of polypeptide chain initiation. Cell 57, 947-954. 

That this translational system can indeed detect a different (increased) translational activity when the extracts are programmed with capped mRNA can be seen from the results presented in Fig. 12.3C. On the other hand, a general reduction of the translational efficiency caused by... 

The most extensively investigated polymorphism is a variation of the number of TA repeats (A(TA) TAA, n = 5-8) in the promoter region. The wild-type allele contains six [(TA)6] repeats that are located -53 to -A2 from the translational start codon. UGT1A1 28 [(TA)7], a common variation in Gilbert s syndrome (25,26), has an in vitro translational activity that is 63% of the wild-type allele (27). Minor TA variations include 36 n = 5) and 37 n= 8), which result in enhanced and reduced, respectively, transcriptional activity in vitro (Table 1). 

The importance of lattice coupling in direct molecular dissociation is at present poorly understood. However, there are at least two ways in which inclusion of the lattice can affect direct dissociative adsorption. First, conversion of Et to Eq competes with translational activation in dissociation. Second, thermal distortion of lattice atoms from their equilibrium positions may affect the PES, e.g., the barriers to dissociation V ( ). These two effects can be most simply thought of as a phonon induced modulation of the barrier along the translational coordinate and in amplitude, respectively. 

This constitutive, post-translationally activated enzyme enables plant cells to respond very rapidly to metal ions entering the cell. 

The slowest process will be the vibration-translation activation to the (v = 1) level, which will be rate-determining, and the subsequent vibration-vibration transfers will occur at increasingly fast rates with increasing vibrational quantum number. (For harmonic oscillators 1 = n(m+ l) 1 .) Shock-tube experi-... 

Matsumoto, K., Wassarman, K.M. and Wollfe, A.P. (1998) Nuclear history of a pre-mRNA determines the translational activity of cytoplasmic mRNA. EMBO J., 17,2107-2121. 

The cell-free system prepared from washed embryos has much higher translational activity than the conventional system (compare Fig. 3A and B). When 5 -capped dihydrofolate reductase (DHFR) mRNA containing 549 nt of 3 UTR with a pA tail was incubated with newly prepared as well as conventional extract, there was almost linear kinetics in DHFR synthesis over 4 h, compared with the regular system, which ceased to function after 1.5 h. Further, when washed extract in the reaction volume was increased to 48%, amino acid incorporation occurred initially at a rate twice that of 24% extract, and then stopped after 1 h. However, this pause was caused by a shortage of substrates rather than an irreversible inactivation of ribosomes or factors necessary for translation addition of amino acids, ATP, and GTP after cessation of the reaction (arrow) restarted... 

Park KS, Sohn DH, Veech RL, et al. Translational activation of ethanol-inducible cytochrome P450 (CYP2E1) by isoniazid. Eur J Pharmacol 1993 248 7-14. 

In Fig. 14 we show HREEL spectra of ethylene adsorbed at Ag(4 1 0) and at Ag(2 1 0) at T = 105 K and compare them with the spectra recorded for Ag(l 00). On stepped surfaces (upper two spectra) C2H4 was dosed with a pure beam. Non-activated adsorption is witnessed by the loss in the 121-125 meY region. No adsorption takes place, on the other hand, on the extended (100) terraces of Ag(l 00) [90] up to much higher energies (see spectrum recorded at Ex = 0.31 eV in Fig. 14). Chemisorption on Ag(l 0 0) is observed when the ethylene exposure is performed with Ex — 0.35 eV. Adsorption on the flat surface is therefore translationally activated for extended (100) terraces and non activated for stepped surfaces. Physisorbed molecules do not contribute to the HREEL spectra since desorption takes place within a few seconds after the end of the dose at 105 K (as evident from Fig. 2) and recording a spectrum requires many minutes. 

---