Thank you As you know, protein kinase A phosphorylates amino acid residues on ta

Question

Thank you

As you know, protein kinase A phosphorylates amino acid residues on target proteins that are part of a specific peptide region. An antibody raised against the phosphorylated form of this peptide (phospho- PKA substrate antibody) can be used to identify and study PKA-phosphorylated target proteins Figure 1 shows the results of an experiment in which cell extracts were in vitro phosphorylated by protein kinase A, in the absence (Sample 3) or presence (Sample 4) of a PKA inhibitor (PKI). For comparison, two other protein kinases, extracellular signal-regulated kinase 2 (ERK2; sample 6) and a CyclinA/Cdkl complex (sample 8) were also tested with the same cell extract. Mixtures without cell extracts (Sample 2, 5, and 7) served as control samples. After incubation samples were subjected to SDS-polyacrylamide gel electrophoresis and Western blot analysis using the phospho-PKA substrate antibody

Explanation / Answer

10. E. It corresponds to a protein phosphorylated by endogenous PKA before the in vitro reaction was started.

11. C. It corresponds to a protein contaminating the PKA preparation and phosphorylated by PKA
before the in vitro reaction was started.

Related Questions

Navigate

• Browse (All)
• Browse T
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.