Table 2 Features of enhancer-promoter contacts (EPC)

EPC is pervasive genome-wide

[170,171,172,173,174]

 Facultative (de novo): formed on demand for transcription

[128, 129, 144, 175, 176]

 Preformed: keeps gene loci poised for transcription

[170, 177,178,179,180]

EPC correlates with active transcription

[128, 181,182,183]

EPC is required for transcription or “forced” EPC results in transcription

[184,185,186,187]

EPC is required for PIC recruitment, transcription elongation

[91, 188, 189]

Promoters in contact with active enhancers exhibit higher transcription rates

[170]

Sustained transcription is not required for the maintenance of EPC

[170, 190]

Proteins of various structural and functional categories can act as looping factors promoting EPC: tissue-specific TFs, Mediator complex, the Cohesin complex, CTCF; bridging factors LDB1, GATA3, OCA-B coactivator; chromatin remodelers SWI/SNF and NuRD; SRC-3; YY-1

[95, 128, 176, 187, 191,192,193,194,195,196,197,198,199,200]