Linkers have the following two applications: creation of cohesive 'ends

on blunt~ended DNA fragments, and 

on fragments having unmatched or undefined sequences in their protruding ends. 

TLS Online TPP Program

#Id: 10006

#Unit 4. Cell Communication and Cell Signaling

Hedgehog protein with autoproteolytic activity that cleaves off the C-terminus to reveal a signal sequence that marks the protein for secretion.

TLS Online TPP Program

#Id: 10007

#Unit 4. Cell Communication and Cell Signaling

TLS Online TPP Program

#Id: 10008

#Unit 4. Cell Communication and Cell Signaling

The freed C-terminal is not involved in signaling and is often degraded, whereas the N-terminal becomes the active Hedgehog protein intended for secretion

TLS Online TPP Program

#Id: 10009

#Unit 4. Cell Communication and Cell Signaling

Secretion requires the addition of cholesterol and palmitic acid to the Hedgehog protein

TLS Online TPP Program

#Id: 10010

#Unit 4. Cell Communication and Cell Signaling

Two membrane proteins, 

Smoothened (Smo) 

Patched (Ptc)

TLS Online TPP Program

#Id: 10011

#Unit 4. Cell Communication and Cell Signaling

Smo has seven TM α helices, is a member of the GPCR superfamily, and is related in sequence to the Fz.