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Different types of cell surface receptors that receive and transmit signals.

Cell surface receptors that use G-proteins to transduce signals.

Cell surface receptors that phosphorylate tyrosine residues upon ligand binding, initiating downstream signaling cascades.

Process by which a cell converts one kind of signal or stimulus into another.

Membrane channels that open or close in response to a specific ligand binding.

Inside cell receptors that bind steroid hormones, regulating gene expression.

Cyclic AMP: A second messenger involved in various cellular responses.

Intracellular molecules that relay signals from receptors to target molecules in a cell.

Transmembrane receptors with intracellular tyrosine kinase activity, activated by ligand binding.

Two receptor proteins come together when a ligand binds to both simultaneously.

Two ligands bind separate receptors, making them join together.

Proteins that span the cell membrane, with parts inside and outside the cell.

A molecule that binds to a receptor.

The part of a receptor protein inside the cell.

The ability of a protein to add phosphate groups to other proteins.

When a growth factor binds to an RTK, the receptor phosphorylates itself on tyrosine residues in its intracellular domain.

The process where the activated RTK phosphorylates other RTK molecules within the same signaling complex.

Proteins that are recruited to the phosphorylated RTK and become activated, relaying the signal further into the cell.

Specialized domains in relay proteins that recognize and bind to phosphotyrosine residues on activated RTKs.

Another type of domain in relay proteins that binds to phosphotyrosine residues, similar to SH2.

Cells must have a way to stop responding to signals to maintain normal function.

The process where the CBL protein attaches ubiquitin molecules to RTKs, marking them for destruction.

The process where the cell engulfs and destroys or recycles the ligand-receptor complex.

Ubiquitinated RTKs are taken to the lysosome, a cellular organelle that breaks down waste.

Proteins that act as linkers, connecting different signaling components.

When a ligand binds to a Receptor Tyrosine Kinase (RTK), it triggers a conformational change, causing the receptor to dimerize (form a pair) and activate its tyrosine kinase activity.

Once activated, the RTK's tyrosine kinase domain adds phosphate groups (phosphorylates) to tyrosine residues within the receptor itself or other proteins, initiating downstream signaling cascades.

One pathway activated by RTKs involves PI3 kinase (PI3K) which phosphorylates lipids (PIP2 → PIP3) in the cell membrane. This recruits proteins like Akt to the membrane, which then gets activated by phosphorylation.

Once Akt is recruited to the membrane, it gets phosphorylated by PDK1 and PDK2, leading to its activation.

Another major pathway activated by RTKs involves Ras, a GTP-binding protein. When activated, Ras triggers a signaling cascade that culminates in the activation of MAPK.

Glucagon is a hormone released from the pancreas when blood glucose levels are low. It stimulates the liver to break down glycogen and release glucose into the bloodstream, raising blood sugar.

Epinephrine, also known as adrenaline, is released from the adrenal glands during stress or 'fight-or-flight' situations. It activates receptors in the liver, leading to glycogen breakdown and glucose release, providing energy for the body.

Insulin is a hormone released from the pancreas when blood glucose levels are high. It stimulates cells to take up glucose and store it as glycogen, lowering blood sugar.

GPCRs (G protein-coupled receptors) are a class of cell surface receptors that use G proteins to transmit signals inside the cell. This type of signaling pathway is involved in responses to hormones like glucagon and epinephrine.

RTKs (receptor tyrosine kinases) are another type of cell surface receptor that use tyrosine kinase activity to transmit signals. Insulin utilizes this pathway to regulate glucose uptake and storage.

Insulin signaling involves the interaction of insulin with its receptor, leading to the activation of Insulin Receptor Substrate 1 (IRS1). This triggers multiple downstream signaling cascades within the cell.

One of the key signaling pathways activated by insulin/IRS1. This pathway involves PLCγ (phospholipase C-gamma) which generates second messengers IP3 and DAG, leading to various cellular responses.

Another important signaling pathway activated by insulin/IRS1. PIP3 (phosphatidylinositol (3,4,5)-trisphosphate) activates AKT, a protein kinase that plays a crucial role in promoting cell growth and survival.

Insulin is a key hormone regulating blood glucose levels. It promotes uptake of glucose by cells and its storage as glycogen, helping to lower blood sugar.

Signaling pathways, such as those involving GPCRs, RTKs, and insulin/IRS1, allow cells to respond to external stimuli and regulate essential cellular processes.

Receptor tyrosine kinases (RTKs) are transmembrane proteins with tyrosine kinase activity in their intracellular domain. They bind to ligands like growth factors, triggering dimerization and autophosphorylation.

Ligand binding to RTKs causes them to dimerize, forming a pair. This dimerization activates the tyrosine kinase activity within the receptor.

RTK signaling must be terminated to prevent uncontrolled cell growth. This is achieved through ubiquitination and receptor-mediated endocytosis.

Common RTK ligands include insulin, vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF). RTKs play crucial roles in cell growth, survival, and differentiation.

Specialized domains in relay proteins that recognize and bind to the phosphate groups added to the RTK.

Proteins that connect different components of a signaling complex.

Proteins that act as binding sites for multiple signaling proteins.

Receptor tyrosine kinases (RTKs) are transmembrane proteins that act as signal receivers on the cell surface.

Ligand binding causes RTKs to dimerize, forming a pair. This activates their tyrosine kinase activity, allowing them to phosphorylate themselves and other proteins.

RTKs activate three crucial signaling pathways: 1. PLCγ → IP3/DAG, 2. PIP3 → AKT, and 3. Ras → MAPK.

The Ras pathway, activated by RTKs, is crucial for cell growth and proliferation. It involves a series of proteins that ultimately activate MAPK, a key regulator of cell division.

Cells must turn off RTK signals to prevent uncontrolled growth. This happens through ubiquitination of the RTKs, marking them for destruction by the lysosomes.

Receptor tyrosine kinases (RTKs) can activate multiple relay proteins simultaneously, leading to diverse cellular responses.

RTKs activate three primary signaling pathways: 1. PLCγ → IP3/DAG, 2. PIP3 → AKT, and 3. Ras → MAPK.

Phospholipase C-γ (PLCγ) is a relay protein that binds to activated RTKs via its SH2 domain.

Tyrosine phosphorylation of PLCγ increases its activity, enabling it to cleave PIP2 into IP3 and DAG.

IP3 and DAG act as second messengers, triggering downstream signaling events, such as calcium release and protein kinase C activation.

Both GPCRs and RTKs can lead to IP3 and DAG production, however, the activation mechanisms differ.

SH2 domains are specialized protein domains that recognize and bind to phosphotyrosine residues on activated RTKs.

G-protein coupled receptors (GPCRs) are cell surface receptors that use G-proteins to transmit signals inside the cell. They are involved in responses to hormones like glucagon and epinephrine.

The PIP3 → AKT pathway is a crucial insulin signaling pathway. PIP3 activates AKT, a protein kinase that promotes cell growth and survival.

Signaling pathways, like the ones involving GPCRs, RTKs, and insulin/IRS1, allow cells to respond to external stimuli and regulate essential cellular processes.

Receptor tyrosine kinases (RTKs) are transmembrane proteins with tyrosine kinase activity. They bind to ligands, triggering dimerization and autophosphorylation.

RTK signaling needs to be terminated to prevent uncontrolled cell growth. This occurs through ubiquitination and receptor-mediated endocytosis.

Receptor tyrosine kinases (RTKs) are transmembrane proteins with tyrosine kinase activity in their intracellular domain. They bind to ligands such as growth factors and activate signaling pathways.

Ligand binding to RTKs causes them to dimerize (form a pair). This activates their tyrosine kinase activity, allowing them to phosphorylate themselves and other proteins.

Activated RTKs trigger downstream signaling cascades, leading to diverse cellular responses, including changes in gene expression, cell growth, and metabolism.

Activated RTKs can trigger multiple signaling pathways, including the PI3K pathway, Ras pathway, and PLCγ pathways.

Common RTK ligands include insulin, vascular endothelial growth factor (VEGF), and epidermal growth factor (EGF).

Dysregulation of RTK signaling is linked to various diseases, including cancer, due to uncontrolled cell growth and proliferation.

SH2 and PTB domains are protein domains that recognize and bind to phosphotyrosine residues on activated RTKs, mediating protein interactions and relaying signals.

The Ras/MAPK signaling pathway is a chain reaction of protein activation triggered by a variety of signals, including growth factors and hormones. It's crucial for cell growth, proliferation, and differentiation.

A relay system of proteins involved in the Ras/MAPK signaling pathway. Activated Ras triggers a series of phosphorylation events, activating MAPKKK, MAPKK, and finally MAPK.

MAPKs (mitogen-activated protein kinases) are a family of protein kinases essential for regulating various cellular functions. They manage cell proliferation, gene expression, differentiation, and apoptosis.

1. Growth factor binds to the receptor. 2) Grb2 (adaptor protein) and SOS proteins are recruited. 3) Ras exchanges GDP for GTP. 4) Activated Ras binds to and phosphorylates Raf, activating it, leading to a downstream signaling cascade.

Epinephrine (also known as adrenaline) is released from the adrenal glands during stress or 'fight-or-flight' situations. It activates receptors in the liver, leading to glycogen breakdown and glucose release, providing energy for the body.

GPCRs are cell surface receptors that use G-proteins to transmit signals inside the cell. This type of signaling pathway is involved in responses to hormones like glucagon and epinephrine.

RTKs are another type of cell surface receptor that use tyrosine kinase activity to transmit signals. Insulin utilizes this pathway to regulate glucose uptake and storage.