protein phosphatase 2B binding

Definition

Target type: molecularfunction

Binding to a protein phosphatase 2B. [GOC:jl]

Protein phosphatase 2B (PP2B), also known as calcineurin, is a calcium/calmodulin-dependent serine/threonine protein phosphatase. It plays a critical role in various cellular processes, including signal transduction, gene expression, neuronal function, and immune responses. PP2B binding is crucial for its activation and regulation.

PP2B is composed of two subunits: a catalytic subunit (PP2Bα or PP2Bβ) and a regulatory subunit (calmodulin). The catalytic subunit contains the phosphatase activity, dephosphorylating target proteins. Calmodulin acts as a calcium sensor, binding to the catalytic subunit in response to increased intracellular calcium levels. This calcium-dependent binding activates PP2B, enabling it to dephosphorylate its substrates.

PP2B binding to target proteins is a complex process involving multiple factors. The specific binding site on PP2B varies depending on the interacting protein. In some cases, the binding site is located on the catalytic subunit, while in others, it is on the calmodulin subunit.

The molecular function of PP2B binding can be summarized as follows:

* **Activation:** PP2B binding to calmodulin is essential for its activation. Calcium binding to calmodulin induces a conformational change that exposes the active site of the catalytic subunit, allowing it to dephosphorylate target proteins.
* **Regulation:** PP2B binding to regulatory proteins, such as inhibitor-1 (I-1), can inhibit its activity. I-1 binds to the catalytic subunit, preventing substrate access and inhibiting phosphatase activity.
* **Substrate specificity:** PP2B binding to specific target proteins determines its substrate specificity. The binding interaction can be modulated by post-translational modifications, such as phosphorylation, or by the presence of other interacting proteins.
* **Signal transduction:** PP2B binding to signaling molecules, such as NFAT (nuclear factor of activated T cells), plays a critical role in signal transduction pathways. PP2B dephosphorylates NFAT, allowing it to translocate to the nucleus and regulate gene expression.
* **Cellular processes:** PP2B binding is involved in various cellular processes, including neuronal function, immune responses, muscle contraction, and cell growth.

In summary, PP2B binding is a crucial mechanism for regulating its activity and influencing a wide range of cellular processes.'
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Proteins (3)

Compounds (11)