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Mechanisms and proteins involved in long-distance interactions.

Maksimenko O, Georgiev P - Front Genet (2014)

Bottom Line: Due to advances in genome-wide technologies, consistent distant interactions within chromosomes of higher eukaryotes have been revealed.In particular, it has been shown that enhancers can specifically and directly interact with promoters by looping out intervening sequences, which can be up to several hundred kilobases long.Available data are in agreement with the model that several known transcription factors and insulator proteins belong to an abundant but poorly studied class of proteins that are responsible for chromosomal architecture.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences Moscow, Russia.

ABSTRACT
Due to advances in genome-wide technologies, consistent distant interactions within chromosomes of higher eukaryotes have been revealed. In particular, it has been shown that enhancers can specifically and directly interact with promoters by looping out intervening sequences, which can be up to several hundred kilobases long. This review is focused on transcription factors that are supposed to be involved in long-range interactions. Available data are in agreement with the model that several known transcription factors and insulator proteins belong to an abundant but poorly studied class of proteins that are responsible for chromosomal architecture.

No MeSH data available.


Two modes of pairing between two copies of an insulator inserted in either (A) opposite or (B) same orientation. Presumptive proteins responsible for insulator pairing are shown as a cluster of yellow, green, blue boxes. Red box with solid arrow indicates promoter region, orange oval – enhancer element.
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Figure 2: Two modes of pairing between two copies of an insulator inserted in either (A) opposite or (B) same orientation. Presumptive proteins responsible for insulator pairing are shown as a cluster of yellow, green, blue boxes. Red box with solid arrow indicates promoter region, orange oval – enhancer element.

Mentions: As shown in transgenic lines, pairing of two identical insulators can support distant activation of a promoter by an enhancer or yeast GAL4 activator (Cai and Shen, 2001; Muravyova et al., 2001; Kyrchanova et al., 2007; Kyrchanova et al., 2008a, b). The relative orientation of two identical insulators defines the mode of loop formation that either allows or blocks enhancer (GAL4)–promoter interaction (Kyrchanova et al., 2008a,b). This phenomenon is explained by the assumption that when the insulators are located in opposite orientations, the loop configuration is favorable for communication between regulatory elements located beyond the loop (Figure 2). The loop formed by two insulators located in the same orientation juxtaposes two elements located within and beyond the loop. Supposedly, this orientation-dependent interaction is accounted for by at least two insulator-bound proteins that are involved in specific protein–protein interactions.


Mechanisms and proteins involved in long-distance interactions.

Maksimenko O, Georgiev P - Front Genet (2014)

Two modes of pairing between two copies of an insulator inserted in either (A) opposite or (B) same orientation. Presumptive proteins responsible for insulator pairing are shown as a cluster of yellow, green, blue boxes. Red box with solid arrow indicates promoter region, orange oval – enhancer element.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3927085&req=5

Figure 2: Two modes of pairing between two copies of an insulator inserted in either (A) opposite or (B) same orientation. Presumptive proteins responsible for insulator pairing are shown as a cluster of yellow, green, blue boxes. Red box with solid arrow indicates promoter region, orange oval – enhancer element.
Mentions: As shown in transgenic lines, pairing of two identical insulators can support distant activation of a promoter by an enhancer or yeast GAL4 activator (Cai and Shen, 2001; Muravyova et al., 2001; Kyrchanova et al., 2007; Kyrchanova et al., 2008a, b). The relative orientation of two identical insulators defines the mode of loop formation that either allows or blocks enhancer (GAL4)–promoter interaction (Kyrchanova et al., 2008a,b). This phenomenon is explained by the assumption that when the insulators are located in opposite orientations, the loop configuration is favorable for communication between regulatory elements located beyond the loop (Figure 2). The loop formed by two insulators located in the same orientation juxtaposes two elements located within and beyond the loop. Supposedly, this orientation-dependent interaction is accounted for by at least two insulator-bound proteins that are involved in specific protein–protein interactions.

Bottom Line: Due to advances in genome-wide technologies, consistent distant interactions within chromosomes of higher eukaryotes have been revealed.In particular, it has been shown that enhancers can specifically and directly interact with promoters by looping out intervening sequences, which can be up to several hundred kilobases long.Available data are in agreement with the model that several known transcription factors and insulator proteins belong to an abundant but poorly studied class of proteins that are responsible for chromosomal architecture.

View Article: PubMed Central - PubMed

Affiliation: Laboratory of Gene Expression Regulation in Development, Institute of Gene Biology, Russian Academy of Sciences Moscow, Russia.

ABSTRACT
Due to advances in genome-wide technologies, consistent distant interactions within chromosomes of higher eukaryotes have been revealed. In particular, it has been shown that enhancers can specifically and directly interact with promoters by looping out intervening sequences, which can be up to several hundred kilobases long. This review is focused on transcription factors that are supposed to be involved in long-range interactions. Available data are in agreement with the model that several known transcription factors and insulator proteins belong to an abundant but poorly studied class of proteins that are responsible for chromosomal architecture.

No MeSH data available.