In Wnt-Ca2+ pathway, Wnt binding to the receptor protein possibly Ryk, alone or in concert with Frizzled.

TLS Online TPP Program

#Id: 6891

#Unit 3. Fundamental Processes

The Xist transcript is regulated in a negative manner by Tsix, its antisense partner.

TLS Online TPP Program

#Id: 6892

#Unit 3. Fundamental Processes

To modify DNA at a new position requires the action of a de novo methyltransferase, which recognizes DNA by virtue of a specific sequence. It acts only on unmethylated DNA to add a methyl group to one strand.

TLS Online TPP Program

#Id: 6893

#Unit 3. Fundamental Processes

There are two de novo methyltransferases (Dnmt3A and Dnmt3B) in the mouse; they have different target sites, and both are essential for development.

TLS Online TPP Program

#Id: 6894

#Unit 3. Fundamental Processes

A maintenance methyltransferase acts constitutively only on hemimethylated sites to convert them to fully methylated sites. Its existence means that any methylated site is perpetuated after replication.  There is one maintenance methyltransferase (Dnmt1) in mice, and it is essential.

TLS Online TPP Program

#Id: 6895

#Unit 3. Fundamental Processes

UHRF1, that is important for the maintenance of methylation both locally and globally through its association with Dnmt1.

TLS Online TPP Program

#Id: 6896

#Unit 3. Fundamental Processes

UHRF1 also interacts with methylated histone H3, which connects the maintenance of DNA methylation with the stabilization of heterochromatin structure