Search results
Results From The WOW.Com Content Network
Transcriptional repressor CTCF also known as 11-zinc finger protein or CCCTC-binding factor is a transcription factor that in humans is encoded by the CTCF gene. [ 5 ] [ 6 ] CTCF is involved in many cellular processes, including transcriptional regulation , insulator activity, V(D)J recombination [ 7 ] and regulation of chromatin architecture.
CTCF molecules can form homodimers on DNA, which can be co-bound by cohesin; this chromatin loop structure helps constrain the ability of enhancers within the loop to target genes outside the loop. Loops with CTCF and cohesin at the start and end of the loop that restrict enhancer-gene targeting are "insulated neighborhoods."
CTCF forms methylation-sensitive insulators that regulate X-chromosome inactivation. Transcriptional repressor CTCFL (this protein) is a paralog of CTCF and appears to be expressed primarily in the cytoplasm of spermatocytes, unlike CTCF which is expressed primarily in the nucleus of somatic cells. CTCF and CTCFL are normally expressed in a ...
Moreover, CTCF and cohesin play important roles in determining TADs and enhancer-promoter interactions. The result shows that the orientation of CTCF binding motifs in an enhancer-promoter loop should be facing to each other in order for the enhancer to find its correct target.
From its first version Excel supported end-user programming of macros (automation of repetitive tasks) and user-defined functions (extension of Excel's built-in function library). In early versions of Excel, these programs were written in a macro language whose statements had formula syntax and resided in the cells of special-purpose macro ...
TAD locations are defined by applying an algorithm to Hi-C data. For example, TADs are often called according to the so-called "directionality index". [5] The directionality index is calculated for individual 40kb bins, by collecting the reads that fall in the bin, and observing whether their paired reads map upstream or downstream of the bin (read pairs are required to span no more than 2Mb).
This process continues until the extruding complex is released or encounters a barrier. In vertebrates, one well-studied factor that limits loop extrusion by cohesin is the CCCTC-binding factor (CTCF). CTCF directly interacts with cohesin, stabilizing it on chromatin and anchoring loop boundaries.
In Microsoft Excel, these functions are defined using Visual Basic for Applications in the supplied Visual Basic editor, and such functions are automatically accessible on the worksheet. Also, programs can be written that pull information from the worksheet, perform some calculations, and report the results back to the worksheet.