Eukaryotic gene expression

Li, G. Laszio, A. (1985). Thermotolerance in mammalian cells A possible role for the heat shock proteins. In Changes in Eukaryotic Gene Expression in Response to Environmental Stress (Atkinson, B.G. Walden, D.B. eds.), pp. 349-371, Academic Press, Orlando. 

Chromatin Remodeling Is an Important Aspect of Eukaryotic Gene Expression... 

Chen B, Pogue BW, Hoopes PJ, Hasan T (2006) Vascular and cellular targeting for photodynamic therapy. Critical Reviews in Eukaryotic Gene Expression 16 279-305. 

Other mechanisms are important, and, especially in eukaryotes, gene expression is controlled at multiple levels. 

Beyond the modulation of eukaryotic gene expression, histone acetylation has also been functionally linked to histone deposition during DNA replication (see Ref. [146] for a review) and in the displacement/replacement of histones by protamines during spermiogenesis in those vertebrate (see Ref. [147] for a review) and invertebrate organisms [148] whose sperm chromatin consists of protamines [118]. 

Trievel, R.C. (2004) Structure and function of histone methyltransferases. Critical Reviews in Eukaryotic Gene Expression,... 

Initiation of transcription is a crucial regulation point for both prokaryotic and eukaryotic gene expression. Although some of the same regulatory mechanisms are used in both systems, there is a fundamental difference in the regulation of transcription in eukaryotes and bacteria. 

Eukaryotic Gene Expression Can Be Regulated by Intercellular and Intracellular Signals... 

Because of the longer lifetime of eukaryotic messengers, it seems likely that translation level controls should play a greater role in regulation of eukaryotic gene expression. Despite this belief, few mechanisms have been elucidated. 

For eukaryotic genes, expression in insect cells (Baculovirus system) or mammalian cells (Chinese hamster ovary cells, cos7 monkey cells) is possible and is often more likely to lead to active protein than in bacteria or yeast owing to a more efficient posttranslational machinery. However, expression rates are very low and not feasible for production of biocatalysts. 

Fritzsche W, Takac L, Henderson E (1997) Crit Rev Eukaryotic Gene Expression 7 231... 

Wilson, C., Bellen, H.J., and Gehring, W.J. (1990) Position effects on eukaryotic gene expression. Annu. Rev. Cell. Biol. 6, 679-714. 

The information problem of eukaryotic gene expression therefore consists of several components gene recognition, gene transcription, and mRNA processing. These problems have been approached biochemically by analyzing the enzyme systems involved in each step. 

All classes of RNA transcripts must be processed into mature species. The reactions include several types Nucleolytic cleavage, as in the separation of the mature rRNA species from the primary transcript of RNA polymerase I action Chain extension (non-template-directed), as in the synthesis or regeneration of the common CCA sequence at the 3 end of transfer RNAs or of PolyA at the 3 end of mRNAs and Nucleotide modification, for example, the synthesis of methylated nucleotides in tRNA or rRNA. These reactions are a feature of both prokaryotic and eukaryotic gene expression, and the biological consequences are diverse. For example, modified nucleotides can affect the way in which a tRNA recognizes different codons. 

Transcriptional initiation is the most important mode for control of eukaryotic gene expression. Specific factors that exert control include the strength of promoter elements within the DNA sequences of a given gene, the presence or absence of enhancer sequences (which enhance the activity of RNA polymerase at a given promoter by binding specific transcription factors) and the interaction between multiple activator proteins and inhibitor proteins. 

Neddermann P, Gargioli C, Muragha E, Sambucini S, Bonelh E, De Francesco R, Cortese R. A novel, inducible, eukaryotic gene expression system based on the quorum-sensing transcription factor TraR. EMBO Rep. 2003 4 159-165. 

Cis-acting elements constitute only part of the puzzle of eukaryotic gene expression. Transcription factors that bind to these elements also are required. For example, RNA polymerase II is guided to the start site by a set of transcription factors known collectively as TFII (TF stands for transcription factor, and II refers to RNA polymerase II). Individual TFII factors are called TFIIA, TFIIB, and so on. Initiation begins with the binding of TFIID to the TATA box (Figure 28.19). 

In eukaryotes, gene expression is related to the coiling and uncoiling of... 

M. Kalafatis, J. O. Egan, V. K. M. van Cawthem, and K. G. Mann The regulation of clotting factors. Critical Reviews of Eukaryotic Gene Expression 7,241 (1997). 

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