What do nucleotide exchange factors do?

What do nucleotide exchange factors do?

Nucleotide exchange factors (NEFs) are proteins that stimulate the exchange (replacement) of nucleoside diphosphates for nucleoside triphosphates bound to other proteins.

What activates ARF protein?

The cycle of GTP binding and hydrolysis is driven by accessory proteins called guanine nucleotide exchange factors (GEFs) and GTPase-activating proteins (GAPs). Arf GAPs are enzymes that catalyze the hydrolysis of GTP bound to Arf proteins, thereby converting Arf•GTP to Arf•GDP.

What is an ARF GEF?

ARF-GEFs (guanine-nucleotide exchange factors for ADP-ribosylation factor GTPases) are essential for vesicular trafficking in all eukaryotic kingdoms, but of the eight ARF-GEF families, only the ancestral BIG and GBF types are found in plants1,2.

What is the function of ARF?

ARFs have several important functions, including the recruitment of coat proteins that promote sorting of cargo into vesicles, the recruitment and activation of enzymes, such as the phosphatidylinositol (PtdIns) kinases, that alter membrane lipid composition, and interaction with cytoskeletal factors (Table 1).

What are exchange factors?

Exchange factors are enzymes that catalyze the exchange of GTP for GDP on guanine nucleotide binding proteins.

What are ARF GTPases?

ADP-ribosylation factor (Arf) GTPases are a subfamily of the Ras superfamily of small GTPases. Arf proteins perform diverse and critical functions in fundamental cellular processes like membrane trafficking, lipid modification, cytokinesis and cell adhesion.

Is ARF a GEF?

Here we focused on ADP ribosylation factor (Arf) GTPases, which orchestrate a variety of regulatory functions in lipid and membrane trafficking, and their activation by the guanine-nucleotide exchange factor (GEF) Brag2, which controls integrin endocytosis and cell adhesion and is impaired in cancer and developmental …

Where is guanine nucleotide exchange factor?

RCC1 is the guanine nucleotide exchange factor for Ran GTPase. It localizes to the nucleus and catalyzes the activation of Ran to allow nuclear export of proteins. Ephexin5 is a RhoA GEF involved in neuronal synapse development.

What is Ran guanine exchange factor?

Ran Guanine Nucleotide Exchange Factor (RanGEF) promotes the exchange of Ran-bound GDP for GTP on nucleoplasmic side of the nuclear pore as part of the nucleocytoplasmic transport shuttling cycle of Ran.