Signal Transduction

The agonist- induced change in conformation of the receptor causes it to bind, activate, and serve as a substrate for a family of specific receptor kinases, called ________- coupled receptor kinases (GRKs)

________ is synthesized by receptor guanylyl cyclases and soluble cytoplasmic guanylyl cyclases.

________ are cytosolic enzymes that translocate to the plasma membrane upon receptor stimulation.

________: the plasma membrane folds into the cell and makes a small pocket that encloses the material and eventually pinches off to form a vesicle.

Down- regulation: when the number of receptors decrease due to a(n) ________ of a messenger for some time.

________: vesicles in the cytoplasm fuse with the plasma membrane and release their contents outside of the cell.

________: form links between cells, and provide a connection between intermediate filaments of the cell cytoskeletons of adjacent structures- gives strength to tissues.

Up- regulation: when the number of receptors increase due to a(n) ________ of a messenger for some time.

________ (cell eating): large particles, such as bacteria and debris from damaged tissues, are engulfed by the plasma membrane.

________, which have been long associated with receptor desensitization, can also lead to signaling events.

________ the catalyzes the breakdown of ATP to ADP.

________ phosphorylates some of the same substrates as PKA and some that are PKGspecific.

________: charged, so they can not diffuse across the lipid membrane; have special channels created for them.

________- the guanine nucleotide- binding subunit; has innate GTPase activity which acts to terminate the signal.

It uses a(n) ________ as a carrier.

________ are said to move downhill.

Can exist as ________, homodimers, or heterodimers.

Competitively inhibits ________ binding at the active site of the kinase.

________ are classified based on their efficacies for activation of G- proteins.

________: increase the level of PIP3 and PKB (also known as Akt)

Type I: ________ hormones receptors for androgen, estrogen, and.

________ and phosphoinositide second messengers act together to stimulate glucose release.

________- activated protein kinases.

________- mediated mobilization of Ca2+ causes contraction.

________ have 3 subunits.

________: Second messenger- dependent protein kinases not only phosphorylate agonist- activated GPCRs, but also indiscriminately phosphorylate receptors that have not been exposed to agonist.

The ________ also plays a role: molecules diffuse more rapidly in air than in water.

For a given ________, the net flux is affected by several factors.

They require a(n) ________ to transport the ligand.

________- antagonist for beta- 1 and beta- 2 adrenergic receptors, so the drug is going to block both these receptor subtypes on cardiac tissue.

The first messenger binding site has a(n) ________ into which only certain molecules fit.

________ have a wide range of ligands.

________ are classified into six classes based on sequence homology and functional similarities:

________ is polar, but lipids are nonpolar and that is why ________ and lipids do not mix.

If Na+ /________ are on the basal membrane, this moves Na+ out of the cell into the blood by active transport and Na+ from the lumen into the cell by facilitated diffusion.

receives and transmits signal

DNA and RNA production

Since there are no chemical bonds between the fatty acid chains, a lot of lateral movement within the membrane is possible

closely associated with the membrane lipids and are amphipathic proteins

located at the inner or outer membrane surface; do not interact with phospholipid tails

block the flow of fluids between epithelial cells

binding

strength of logan-protein binding

selectivity for one or more ligands

covalent bonding of a charged chemical group by an enzyme to a protein that produces a conformational change to the shape of the protein

a protein contains 2 or more binding sites and the noncovalent binding of a ligand to one site can alter the shape and the characteristics (usually the affinity for a ligand) of the other site

A molecule that binds to a receptor but does not elicit a response

number of receptors in the cell membrane can fluctuate

when the number of receptors decrease due to a high extracellular concentration of a messenger for some time

when the number of receptors increase due to a low extracellular concentration of a messenger for some time

amount of material crossing a surface unit (cm2) per time unit (s)

charged, so they cannot diffuse across the lipid membrane; have special channels created for them

the plasma membrane folds into the cell and makes a small pocket that encloses the material and eventually pinches off to form a vesicle

vesicles in the cytoplasm fuse with the plasma membrane and release their contents outside of the cell

the endocytotic vesicle simply encloses a small volume of ECF

large particles, such as bacteria and debris from damaged tissues, are engulfed by the plasma membrane

Inhibits absorption of cholesterol in the small intestine via the sterol

enzyme that adds phosphate groups

receptors with intrinsic tyrosine kinase activity

intracellular proteins that are responsible to phosphorylating a variety of intracellular proteins on tyrosine residues

Steroid sex hormones receptors for androgen, estrogen, and

Thyroid hormone, vitamin A & D and retinoid receptors

Rhodopsin-like receptors

Metabotropic glutamate receptors

Fungal mating pheromone receptors

Cyclic AMP receptors

Frizzled and Smoothened receptors

Gq

Gi

Gs

Gs

Gi

what if there is a constant presence of ligand/agonist

Specific G protein-coupled receptor kinases (GRKs) selectively phosphorylate agonist-activated receptors

Second messenger-dependent protein kinases not only phosphorylate agonist-activated GPCRs, but also indiscriminately phosphorylate receptors that have not been exposed to agonist

Intestinal mucosa and vascular smooth muscle

complementary phenomenon

depending on their abilities to elicit a receptor-mediated response

antagonist for beta-1 and beta-2 adrenergic receptors, so the drug is going to block both these receptor subtypes on cardiac tissue

model that acknowledges the lateral movement within a cell membrane and accounts for the proteins in the phospholipid bilayer

protein category that includes all amphipathic proteins; associated with membrane lipids; includes transmembrane proteins

protein category that does not span the membrane; inner side is associated with cell shape and motility

cellular connection that blocks the flow of fluids between epithelial cells

cellular connection that forms links between the intermediate filaments of cell's cytoskeletons; gives strength to tissues

cellular connection that forms pores between connecting adjacent cells

newly synthesized polar membrane proteins get to the surface/outside of the cell by being packaged into vesicles by which organelle?

any molecule bound to a protein

strength of ligand-protein binding

selectivity for one or more ligands

covalent bonding of a charged chemical group by an enzyme to a protein that produces a conformational change to a protein

when a protein contains two or more binding sites and non-covalent binding of a ligand to one site can alter the shape/characteristics of another site

response is relayed by another chemical messenger inside the cell

response is relayed by the original chemical messenger

certain molecules can elicit weaker responses on a receptor if they are __________ to the endogenous ligand

degree to which receptors on a cell are occupied by a messenger

chemical messenger that binds to a receptor and triggers the normal response

molecule that binds to a receptor but does not elicit a response

amount of material crossing a surface unit per time unit

net flux = zero

movement of a substance from high concentration of a substance to lower concentration; no energy required