Stimulates the exchange of GDP to GTP on a signaling GTPase, changing its conformation to its active form. Guanine nucleotide exchange factors (GEFs) act by stimulating the release of guanosine diphosphate (GDP) to allow binding of guanosine triphosphate (GTP), which is more abundant in the cell under normal cellular physiological conditions.

Binds to and modulates the activity of a GTPase.

A constituent of the extracellular matrix that enables the matrix to resist longitudinal stress.

A constituent of the extracellular matrix that enables the matrix to resist compressive forces; often a proteoglycan.

OBSOLETE. A constituent of the extracellular matrix that facilitates attachment of cells to the matrix.

A component of the extracellular matrix that enables the matrix to recoil after transient stretching.

The action of a molecule that contributes to the structural integrity of a complex or assembly within or outside a cell, providing elasticity and recoiling.

Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: (R)-carnitine(out) + 4-(trimethylammonio)butanoate(in) = (R)-carnitine(in) + 4-(trimethylammonio)butanoate(out).

Enables the transfer of (R)-carnitine from one side of a membrane to the other.

Enables the transfer of 4-(trimethylammonio)butanoate from one side of a membrane to the other.

Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: solute(out) + cation(in) = solute(in) + cation(out).

Enables the transfer of a solute or solutes from one side of a membrane to the other according to the reaction: sodium(out)+ malonate(out) = sodium(in) + malonate(in).