Biomaterial Database

The ATPase activity of N-ethylmaleimide-sensitive fusion protein (NSF) is regulated by soluble NSF attachment proteins. 1994

A Morgan, and R Dimaline, and R D Burgoyne

Physiological Laboratory, University of Liverpool, United Kingdom.

N-Ethylmaleimide-sensitive fusion protein (NSF) is an ATPase required in multiple stages of the secretory and endocytic pathways. NSF requires other proteins for its action in vesicular transport including the soluble NSF attachment proteins (SNAPs), which act to bind NSF to integral membrane proteins. We have investigated the ATPase activity of NSF and its modulation by alpha- and gamma-SNAPs using His6-tagged recombinant proteins. His6-NSF possessed ATPase activity, which was enhanced in a dose-dependent manner by immobilized (i.e. plastic-adsorbed) but not soluble His6-tagged SNAPs. NSF displayed complex enzyme kinetics consistent with the possession of two ATPase domains with different affinities for ATP. SNAPs apparently enhanced NSF ATPase activity primarily by decreasing the Km of its low affinity site 100-fold. In vivo this effect would be predicted to sensitize the low affinity site to physiological ATP concentrations. Thus SNAPs could act as a molecular switch by "turning on" the normally dormant low affinity ATPase site of NSF.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008565	Membrane Proteins	Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.	Cell Membrane Protein,Cell Membrane Proteins,Cell Surface Protein,Cell Surface Proteins,Integral Membrane Proteins,Membrane-Associated Protein,Surface Protein,Surface Proteins,Integral Membrane Protein,Membrane Protein,Membrane-Associated Proteins,Membrane Associated Protein,Membrane Associated Proteins,Membrane Protein, Cell,Membrane Protein, Integral,Membrane Proteins, Integral,Protein, Cell Membrane,Protein, Cell Surface,Protein, Integral Membrane,Protein, Membrane,Protein, Membrane-Associated,Protein, Surface,Proteins, Cell Membrane,Proteins, Cell Surface,Proteins, Integral Membrane,Proteins, Membrane,Proteins, Membrane-Associated,Proteins, Surface,Surface Protein, Cell
D002352	Carrier Proteins	Proteins that bind or transport specific substances in the blood, within the cell, or across cell membranes.	Binding Proteins,Carrier Protein,Transport Protein,Transport Proteins,Binding Protein,Protein, Carrier,Proteins, Carrier
D004789	Enzyme Activation	Conversion of an inactive form of an enzyme to one possessing metabolic activity. It includes 1, activation by ions (activators); 2, activation by cofactors (coenzymes); and 3, conversion of an enzyme precursor (proenzyme or zymogen) to an active enzyme.	Activation, Enzyme,Activations, Enzyme,Enzyme Activations
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine
D013379	Substrate Specificity	A characteristic feature of enzyme activity in relation to the kind of substrate on which the enzyme or catalytic molecule reacts.	Specificities, Substrate,Specificity, Substrate,Substrate Specificities
D052066	N-Ethylmaleimide-Sensitive Proteins	ATPases that are members of the AAA protein superfamily (ATPase family Associated with Diverse cellular Activities). The NSFs functions, acting in conjunction with SOLUBLE NSF ATTACHMENT PROTEINS (i.e. SNAPs, which have no relation to SNAP 25), are to dissociate SNARE complexes.	N-Ethylmaleimide-Sensitive ATPase,N-Ethylmaleimide-Sensitive Factor,N-Ethylmaleimide-Sensitive Factors,N-Ethylmaleimide-Sensitive Fusion Protein,N-Ethylmaleimide-Sensitive Protein,NEM-Sensitive Fusion Proteins,NSF ATPase,ATPase, N-Ethylmaleimide-Sensitive,ATPase, NSF,N Ethylmaleimide Sensitive ATPase,N Ethylmaleimide Sensitive Factor,N Ethylmaleimide Sensitive Factors,N Ethylmaleimide Sensitive Fusion Protein,N Ethylmaleimide Sensitive Protein,N Ethylmaleimide Sensitive Proteins,NEM Sensitive Fusion Proteins
D052067	Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins	SNARE binding proteins that facilitate the ATP hydrolysis-driven dissociation of the SNARE complex. They are required for the binding of N-ETHYLMALEIMIDE-SENSITIVE PROTEIN (NSF) to the SNARE complex which also stimulates the ATPASE activity of NSF. They are unrelated structurally to SNAP-25 PROTEIN.	Soluble N-Ethylmaleimide-Sensitive Factor Attachment Protein,NSF Attachment Protein,Soluble N-Ethylmaleimide-Sensitive Fusion Attachment Protein,Soluble NSF Attachment Protein,Soluble NSF Attachment Proteins,alpha-SNAP,beta-SNAP,gamma-SNAP,Attachment Protein, NSF,Protein, NSF Attachment,Soluble N Ethylmaleimide Sensitive Factor Attachment Protein,Soluble N Ethylmaleimide Sensitive Factor Attachment Proteins,Soluble N Ethylmaleimide Sensitive Fusion Attachment Protein,alpha SNAP,beta SNAP,gamma SNAP
D033921	Vesicular Transport Proteins	A broad category of proteins involved in the formation, transport and dissolution of TRANSPORT VESICLES. They play a role in the intracellular transport of molecules contained within membrane vesicles. Vesicular transport proteins are distinguished from MEMBRANE TRANSPORT PROTEINS, which move molecules across membranes, by the mode in which the molecules are transported.	Transport Proteins, Vesicular