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.

A metallic element that has the atomic symbol Mg, atomic number 12, and atomic weight 24.31. It is important for the activity of many enzymes, especially those involved in OXIDATIVE PHOSPHORYLATION.

A nucleoside that is composed of ADENINE and D-RIBOSE. Adenosine or adenosine derivatives play many important biological roles in addition to being components of DNA and RNA. Adenosine itself is a neurotransmitter.

A group of enzymes that catalyze the hydrolysis of diphosphate bonds in compounds such as nucleoside di- and tri-phosphates, and sulfonyl-containing anhydrides such as adenylylsulfate. (Enzyme Nomenclature, 1992) EC 3.6.

A subclass of adenosine A2 receptors found in LEUKOCYTES, the SPLEEN, the THYMUS and a variety of other tissues. It is generally considered to be a receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.

An enzyme which catalyzes the hydrolysis of nucleoside triphosphates to nucleoside diphosphates. It may also catalyze the hydrolysis of nucleotide triphosphates, diphosphates, thiamine diphosphates and FAD. The nucleoside triphosphate phosphohydrolases I and II are subtypes of the enzyme which are found mostly in viruses.

A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of tissues including the BRAIN and DORSAL HORN NEURONS. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.

An enzyme that catalyzes the hydrolysis of ADENOSINE to INOSINE with the elimination of AMMONIA.

A sub-family of RHO GTP-BINDING PROTEINS that is involved in regulating the organization of cytoskeletal filaments. This enzyme was formerly listed as EC 3.6.1.47.

A subtype of ADENOSINE RECEPTOR that is found expressed in a variety of locations including the BRAIN and endocrine tissues. The receptor is generally considered to be coupled to the GI, INHIBITORY G-PROTEIN which causes down regulation of CYCLIC AMP.

Enzymes that hydrolyze GTP to GDP. EC 3.6.1.-.

A subclass of adenosine A2 receptors found in the CECUM, the COLON, the BLADDER, and a variety of other tissues. It is generally considered to be a low affinity receptor for ADENOSINE that couples to the GS, STIMULATORY G-PROTEIN.

An enzyme that catalyzes the formation of ADP plus AMP from adenosine plus ATP. It can serve as a salvage mechanism for returning adenosine to nucleic acids. EC 2.7.1.20.

A member of the Rho family of MONOMERIC GTP-BINDING PROTEINS. It is associated with a diverse array of cellular functions including cytoskeletal changes, filopodia formation and transport through the GOLGI APPARATUS. This enzyme was formerly listed as EC 3.6.1.47.

A subclass of ADENOSINE RECEPTORS that are generally considered to be coupled to the GS, STIMULATORY G-PROTEIN which causes up regulation of CYCLIC AMP.

Compounds that selectively bind to and activate ADENOSINE A2 RECEPTORS.

A large family of MONOMERIC GTP-BINDING PROTEINS that are involved in regulation of actin organization, gene expression and cell cycle progression. This enzyme was formerly listed as EC 3.6.1.47.

Compounds that selectively bind to and block the activation of ADENOSINE A2 RECEPTORS.

A class of cell surface receptors that prefer ADENOSINE to other endogenous PURINES. Purinergic P1 receptors are widespread in the body including the cardiovascular, respiratory, immune, and nervous systems. There are at least two pharmacologically distinguishable types (A1 and A2, or Ri and Ra).

Compounds that bind to and block the stimulation of ADENOSINE A1 RECEPTORS.

A rac GTP-binding protein involved in regulating actin filaments at the plasma membrane. It controls the development of filopodia and lamellipodia in cells and thereby influences cellular motility and adhesion. It is also involved in activation of NADPH OXIDASE. This enzyme was formerly listed as EC 3.6.1.47.

Compounds that bind to and stimulate ADENOSINE A1 RECEPTORS.

A class of enzymes that transfers nucleotidyl residues. EC 2.7.7.

Compounds that bind to and block the stimulation of PURINERGIC P1 RECEPTORS.

Protein factors that promote the exchange of GTP for GDP bound to GTP-BINDING PROTEINS.

Purine bases found in body tissues and fluids and in some plants.

Compounds that bind to and stimulate PURINERGIC P1 RECEPTORS.

Adenine nucleotide containing one phosphate group esterified to the sugar moiety in the 2'-, 3'-, or 5'-position.