What is a PEST sequence in a protein?
A)a sequence where phosphorylation occurs at every serine and tyrosine
B)a sequence that confers resistance to cathepsin-mediated proteolysis
C)a sequence of phenylalanine-glutamate-serine-threonine that is found in many proteins with half lives less than 2 hours
D)a sequence that causes ubiquitination of the protein followed by degradation
E)none of the above

Question

Quizplus · Accepted Answer

A PEST sequence is a sequence of amino acids that determines the stability and degradation rate of a protein. It contains a high proportion of proline (P), glutamic acid (E), serine (S), and threonine (T) residues, which are the targets for phosphorylation and ubiquitination. The PEST sequence causes ubiquitination of the protein followed by degradation, making option D the correct answer.

What Is a PEST Sequence in a Protein