Glutamine-rich domains

Examples for other trans-activating domains are the glutamine rich domains of the transcription factor Spl and the prohne rich domain of the transcription factor CTF/ NFl, which contains 20 % prohne residues. 

GGGCGG), is usually quite near the TATA box. The DNA-binding domain of the Spl protein is near its carboxyl terminus and contains three zinc fingers. Two other domains in Spl function in activation, and are notable in that 25% of their amino acid residues are Gin. A wide variety of other activator proteins also have these glutamine-rich domains. 

Courey, A.J., Holtzman, D.A., Jackson, S.P. Tjian, R. (1989). Synergistic activation by the glutamine-rich domains of human transcription factor Spl. Cell 59, 827-36. 

Guo L et al (2007) Crystal structure of a conserved N-terminal domain of histone deacetylase 4 reveals functional insights into glutamine-rich domains. Proc Natl Acad Sci USA 104(11) 4297-4302... 

Many protein-protein binding domains also have identifiable motifs, such as acidic domains, glutamine-rich domains, and proline-rich domains. 

Acidic domains, glutamine-rich domains, and proline-rich domains. 

Agianian B, Leonard K, Bonte E, Van der Zandt H, Becker PB, Tucker PA (1999) The glutamine-rich domain of the Drosophila GAGA factor is necessary for amyloid fibre formation in vitro, but not for chromatin remodelling. 1 Mol Biol 285 527-544... 

Perutz, M. F., Pope, B. J., Owen, D., Wanker, E. E., and Scherzinger, E. (2002b). Aggregation of proteins with expanded glutamine and alanine repeats of the glutamine-rich and asparagine-rich domains of Sup35 and of the amyloid /1-peptide of amyloid plaques. Proc. Natl. Acad. Sci. USA 99, 5596-5600. 

In addition to structural domains devoted to DNA binding and dimerization (or oligomerization), many regulatory proteins must interact with RNA polymerase, with unrelated regulatory proteins, or with both. At least three different types of additional domains for protein-protein interaction have been characterized (primarily in eukaryotes) glutamine-rich, proline-rich, and acidic domains, the names reflecting the amino acid residues that are especially abundant. 

FIGURE 28-30 DNA-binding transactivators, (a) Typical DNA-bind-ing transactivators such as CTF1, Gal4p, and Sp1 have a DNA-bind-ing domain and an activation domain. The nature of the activation domain is indicated by symbols ----, acidic Q Q Q, glutamine-rich ... 

The amino acid sequences of mammalian DNA regulatory proteins suggest the existence of at least three different types of activation domains Acidic, glutamine-rich, and proline-rich. 

Cereal prolamins, named glutenins and gliadins in wheat, secalins in rye, and horde-ins in barley, are major storage proteins of the cereal grain endosperm. These sulfur-rich proteins comprise an N-terminal domain of proline- and glutamin-rich repeats and a C-terminal domain responsible for intrachain disulfide bonds (Breiteneder and Radauer 2004). So far, y-3 hordein (Hor v 21) from barley, Sec c 20 from rye, as well as Tri a 19 and Tri a 26 from wheat are included in the IUIS allergen list. 

Glutamine-rich transcription factor Spl is readily cross-linked by TG 2 (Han and Park, 2000). Inasmuch as some TG 2 is present in the nucleus, and Qn domains are excellent substrates, it is possible that TGs may modulate the activity of at least some transcription factors in vivo. Because TG activity is increased in HD brain, and because the expanded Qn domain of Htt is an excellent TG substrate, the possibility exists that TGs play a critical role in altered transcription level and properties in Q -expansion diseases. 

AHR role in gene transcription. The transactivation function of mammalian AHRs has been found to reside in the C-terminal half of the protein and three different structural motifs have been implicated glutamine (Q)-rich, acidic, and proline/ser-ine/threonine (P/S/T)-rich domains . Q-rich regions are missing or reduced in... 

The head and tail domains in keratin molecules generally contain a multitude of sites that allow keratin IFs to form covalent bonds with other proteins. For example, in the case of the keratin IFs in the inner root sheath, lysine to glutamine crosslinks have been characterized between the head and (more often) the tail domains in (generally) both Type I and Type II chains, envoplakin, epiplakin, the SPR2 (small proline-rich) family, and trichohyalin (Steinert et al., 2003). Likewise, in noninner root... 

No common structural motifs are known for the activation domains of transcription factors. Activation domains that are rich in acidic amino acids, glutamines or prolines have been reported. 

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