Related Experiment Video
Updated: Oct 26, 2026

A Mass Spectrometry-Based Approach to Identify Phosphoprotein Phosphatases and their Interactors
Published on: April 29, 2022
Biophysical interaction between phospholamban and protein phosphatase 1 regulatory subunit GM
I Berrebi-Bertrand1, M Souchet, J C Camelin
1SmithKline Beecham Laboratoires Pharmaceutiques, Saint-Grégoire, France. isabelle_bertrand@sbphrd.com
Abstract:
Regulation of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA 2a) depends on the phosphorylation state of phospholamban (PLB). When PLB is phosphorylated, its inhibitory effect towards SERCA 2a is relieved, leading to an enhanced myocardial performance. This process is reversed by a sarcoplasmic reticulum (SR)-associated type 1 protein phosphatase (PP1) composed of a catalytic subunit PP1C and a regulatory subunit GM. Human GM and PLB have been produced in an in vitro transcription/translation system and used for co-immunoprecipitation and biosensor experiments. The detected interaction between the two partners suggests that cardiac PPI is targeted to PLB via GM and we believe that this process occurs with the identified transmembrane domains of the two proteins. Thus, the interaction between PLB and GM may represent a specific way to modulate the SR function in human cardiac muscle.
Related Concept Videos
Amplifying Signals via Enzymatic Cascade
Protein Kinases and Phosphatases
Protein kinases
Many proteins in the cell are regulated by phosphorylation, the addition of a phosphate group. A family of enzymes called kinases...
Calmodulin-dependent Signaling
The Ca2+-CaM complex does not have enzymatic activity by itself. Instead, the complex binds downstream target proteins, including membrane proteins or enzymes,...
IP3/DAG Signaling Pathway
Activation and Inactivation of G Proteins
GTPases and their Regulation
Large G-proteins, also known...

