Cdc42 protein signal transduction

Definition

Target type: biologicalprocess

An intracellular signaling cassette in which a small monomeric GTPase of the Cdc42 subfamily relays a signal. [GOC:mah, PMID:18558478]

Cdc42 is a small GTPase protein that plays a critical role in regulating a wide range of cellular processes, including cell polarity, cytoskeletal organization, cell migration, and cell division. Cdc42 signal transduction is initiated by the binding of guanosine triphosphate (GTP) to the protein, which triggers a conformational change that activates Cdc42. This activation allows Cdc42 to interact with a variety of downstream effector proteins, leading to the initiation of signaling cascades that ultimately control cellular behavior.

The process of Cdc42 signal transduction can be broadly divided into the following steps:

1. **Activation of Cdc42:** The activation of Cdc42 is regulated by a family of guanine nucleotide exchange factors (GEFs), which promote the exchange of GDP for GTP. Activated Cdc42 can then interact with a variety of effector proteins.

2. **Interaction with effector proteins:** Activated Cdc42 interacts with a variety of effector proteins, including:

- **PAK (p21-activated kinase) family kinases:** PAK kinases are involved in a wide range of cellular processes, including cytoskeletal reorganization, cell migration, and gene expression.

- **WASp (Wiskott-Aldrich syndrome protein) family proteins:** WASp proteins are involved in the regulation of actin polymerization, which is essential for cell motility and cell division.

- **IQGAPs (IQ motif containing GTPase activating protein):** IQGAPs are scaffold proteins that link Cdc42 to other signaling pathways, including the Ras pathway.

3. **Downstream signaling:** The interaction of Cdc42 with its effector proteins triggers downstream signaling cascades that regulate cellular behavior. For example, activation of PAK kinases can lead to the phosphorylation of downstream targets, such as LIM kinases, which in turn regulate actin cytoskeleton dynamics.

4. **Inactivation of Cdc42:** The activity of Cdc42 is tightly regulated, and it is inactivated by GTPase-activating proteins (GAPs) which stimulate the hydrolysis of GTP to GDP. This ensures that Cdc42 signaling is transient and does not persist for extended periods.

The precise biological outcomes of Cdc42 signaling depend on the specific effector proteins that are activated, the cellular context, and other signaling inputs. Aberrant Cdc42 signaling has been implicated in a variety of diseases, including cancer and developmental disorders.
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Proteins (1)

Compounds (7)