scholarly journals Differential abilities to engage inaccessible chromatin diversify vertebrate HOX binding patterns

Author(s):  
Milica Bulajić ◽  
Divyanshi Srivastava ◽  
Jeremy S Dasen ◽  
Hynek Wichterle ◽  
Shaun Mahony ◽  
...  

ABSTRACTWhile Hox genes encode for conserved transcription factors (TFs), they are further divided into anterior, central, and posterior groups based on their DNA-binding domain similarity. The posterior Hox group expanded in the deuterostome clade and patterns caudal and distal structures. We aim to address how similar HOX TFs diverge to induce different positional identities. We studied HOX TF DNA-binding and regulatory activity during an in vitro motor neuron differentiation system that recapitulates embryonic development. We find diversity in the genomic binding profiles of different HOX TFs, even among the posterior group paralogs that share similar DNA binding domains. These differences in genomic binding are explained by differing abilities to bind to previously inaccessible sites. For example, the posterior group HOXC9 has a greater ability to bind occluded sites than the posterior HOXC10, producing different binding patterns and driving differential gene expression programs. From these results, we propose that the differential abilities of posterior HOX TFs to bind to previously inaccessible chromatin drive patterning diversification.

Development ◽  
2020 ◽  
Vol 147 (22) ◽  
pp. dev194761 ◽  
Author(s):  
Milica Bulajić ◽  
Divyanshi Srivastava ◽  
Jeremy S. Dasen ◽  
Hynek Wichterle ◽  
Shaun Mahony ◽  
...  

ABSTRACTAlthough Hox genes encode for conserved transcription factors (TFs), they are further divided into anterior, central and posterior groups based on their DNA-binding domain similarity. The posterior Hox group expanded in the deuterostome clade and patterns caudal and distal structures. We aimed to address how similar Hox TFs diverge to induce different positional identities. We studied Hox TF DNA-binding and regulatory activity during an in vitro motor neuron differentiation system that recapitulates embryonic development. We found diversity in the genomic binding profiles of different Hox TFs, even among the posterior group paralogs that share similar DNA-binding domains. These differences in genomic binding were explained by differing abilities to bind to previously inaccessible sites. For example, the posterior group HOXC9 had a greater ability to bind occluded sites than the posterior HOXC10, producing different binding patterns and driving differential gene expression programs. From these results, we propose that the differential abilities of posterior Hox TFs to bind to previously inaccessible chromatin drive patterning diversification.This article has an associated ‘The people behind the papers’ interview.


2004 ◽  
Vol 186 (11) ◽  
pp. 3499-3507 ◽  
Author(s):  
Hao Xu ◽  
Baohua Gu ◽  
B. Tracy Nixon ◽  
Timothy R. Hoover

ABSTRACT Activators of σ54-RNA polymerase holoenzyme couple ATP hydrolysis to formation of an open complex between the promoter and RNA polymerase. These activators are modular, consisting of an N-terminal regulatory domain, a C-terminal DNA-binding domain, and a central activation domain belonging to the AAA+ superfamily of ATPases. The AAA+ domain of Sinorhizobium meliloti C4-dicarboxylic acid transport protein D (DctD) is sufficient to activate transcription. Deletion analysis of the 3′ end of dctD identified the minimal functional C-terminal boundary of the AAA+ domain of DctD as being located between Gly-381 and Ala-384. Histidine-tagged versions of the DctD AAA+ domain were purified and characterized. The DctD AAA+ domain was significantly more soluble than DctD( Δ 1-142), a truncated DctD protein consisting of the AAA+ and DNA-binding domains. In addition, the DctD AAA+ domain was more homogeneous than DctD( Δ 1-142) when analyzed by native gel electrophoresis, migrating predominantly as a single high-molecular-weight species, while DctD( Δ 1-142) displayed multiple species. The DctD AAA+ domain, but not DctD( Δ 1-142), formed a stable complex with σ54 in the presence of the ATP transition state analogue ADP-aluminum fluoride. The DctD AAA+ domain activated transcription in vitro, but many of the transcripts appeared to terminate prematurely, suggesting that the DctD AAA+ domain interfered with transcription elongation. Thus, the DNA-binding domain of DctD appears to have roles in controlling the oligomerization of the AAA+ domain and modulating interactions with σ54 in addition to its role in recognition of upstream activation sequences.


1996 ◽  
Vol 16 (3) ◽  
pp. 792-799 ◽  
Author(s):  
S L Gregory ◽  
R D Kortschak ◽  
B Kalionis ◽  
R Saint

We reported the identification of a new family of DNA-binding proteins from our characterization of the dead ringer (dri) gene of Drosophila melanogaster. We show that dri encodes a nuclear protein that contains a sequence-specific DNA-binding domain that bears no similarity to known DNA-binding domains. A number of proteins were found to contain sequences homologous to this domain. Other proteins containing the conserved motif include yeast SWI1, two human retinoblastoma binding proteins, and other mammalian regulatory proteins. A mouse B-cell-specific regulator exhibits 75% identity with DRI over the 137-amino-acid DNA-binding domains of these proteins, indicating a high degree of conservation of this domain. Gel retardation and optimal binding site screens revealed that the in vitro sequence specificity of DRI is strikingly similar to that of many homeodomain proteins, although the sequence and predicted secondary structure do not resemble a homeodomain. The early general expression of dri and the similarity of DRI and homeodomain in vitro DNA-binding specificity compound the problem of understanding the in vivo specificity of action of these proteins. Maternally derived dri product is found throughout the embryo until germ band extension, when dri is expressed in a developmentally regulated set of tissues, including salivary gland ducts, parts of the gut, and a subset of neural cells. The discovery of this new, conserved DNA-binding domain offers an explanation for the regulatory activity of several important members of this class and predicts significant regulatory roles for the others.


2005 ◽  
Vol 79 (13) ◽  
pp. 8661-8664 ◽  
Author(s):  
Stephen Schuck ◽  
Arne Stenlund

ABSTRACT Viral initiator proteins are polypeptides that form oligomeric complexes on the origin of DNA replication (ori). These complexes carry out a multitude of functions related to initiation of DNA replication, and although many of these functions have been characterized biochemically, little is understood about how the complexes are assembled. Here we demonstrate that loss of one particular interaction, the dimerization between E1 DNA binding domains, has a severe effect on DNA replication in vivo but has surprisingly modest effects on most individual biochemical activities in vitro. We conclude that the dimer interaction is primarily required for initial recognition of ori.


1993 ◽  
Vol 13 (2) ◽  
pp. 852-860
Author(s):  
M B Toledano ◽  
D Ghosh ◽  
F Trinh ◽  
W J Leonard

We previously reported that either oxidation or alkylation of NF-kappa B in vitro abrogates DNA binding. We used this phenomenon to help elucidate structural determinants of NF-kappa B binding. We now demonstrate that Cys-62 of NF-kappa B p50 mediates the redox effect and lies within an N-terminal region required for DNA binding but not for dimerization. Several point mutations in this region confer a transdominant negative binding phenotype to p50. The region is highly conserved in all Rel family proteins, and we have determined that it is also critical for DNA binding of NF-kappa B p65. Replacement of the N-terminal region of p65 with the corresponding region from p50 changes its DNA-binding specificity towards that of p50. These data suggest that the N-terminal regions of p50 and p65 are critical for DNA binding and help determine the DNA-binding specificities of p50 and p65. We have defined within the N-terminal region a sequence motif, R(F/G)(R/K)YXCE, which is present in Rel family proteins and also in zinc finger proteins capable of binding to kappa B sites. The potential significance of this finding is discussed.


2019 ◽  
Vol 75 (a1) ◽  
pp. a203-a203
Author(s):  
Walter J. Chazin ◽  
Agnieszka M. Topolska-Woś ◽  
Norie Sugitani ◽  
John J. Cordoba ◽  
Hyun Suk Kim ◽  
...  

1992 ◽  
Vol 12 (7) ◽  
pp. 3006-3014 ◽  
Author(s):  
E A Golemis ◽  
R Brent

Many studies of transcription activation employ fusions of activation domains to DNA binding domains derived from the bacterial repressor LexA and the yeast activator GAL4. Such studies often implicitly assume that DNA binding by the chimeric proteins is equivalent to that of the protein donating the DNA binding moiety. To directly investigate this issue, we compared operator binding by a series of LexA-derivative proteins to operator binding by native LexA, by using both in vivo and in vitro assays. We show that operator binding by many proteins such as LexA-Myc, LexA-Fos, and LexA-Bicoid is severely impaired, while binding of other LexA-derivative proteins, such as those that carry bacterially encoded acidic sequences ("acid blobs"), is not. Our results also show that DNA binding by LexA derivatives that contain the LexA carboxy-terminal dimerization domain (amino acids 88 to 202) is considerably stronger than binding by fusions that lack it and that heterologous dimerization motifs cannot substitute for the LexA88-202 function. These results suggest the need to reevaluate some previous studies of activation that employed LexA derivatives and modifications to recent experimental approaches that use LexA and GAL4 derivatives to detect and study protein-protein interactions.


1987 ◽  
Vol 7 (12) ◽  
pp. 4582-4584 ◽  
Author(s):  
L Dailey ◽  
S B Roberts ◽  
N Heintz

Specific DNA-binding and in vitro transcription activities of H4TF-1 and H4TF-2 are inactivated by chelating agents. Binding activity is restored by addition of Zn2+, and H4TF-2 is also reactivated by Fe2+. In contrast, preformed factor-DNA complexes are resistant to chelators. Therefore, metal ions are a required component of the H4TF-1 and H4TF-2 DNA-binding domains.


2015 ◽  
Vol 116 (11) ◽  
pp. 2435-2444 ◽  
Author(s):  
Mir A. Hossain ◽  
Joeva J. Barrow ◽  
Yong Shen ◽  
MD Imdadul Haq ◽  
Jörg Bungert

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