Homologous and Heterologous Desensitization Receptor

Flashcards covering homologous and heterologous desensitization, receptors with enzymatic activity, RTKs, and the MAP kinase pathway.

Homologous Desensitization

The process where the same receptor activates the kinase involved in its own phosphorylation, leading to its desensitization.

Heterologous Desensitization

The process where receptor desensitization occurs indirectly, with kinases activated downstream in the signaling cascade (e.g., PKA or PKC) phosphorylating the receptor.

Receptors with Intrinsic Enzymatic Activity

Receptors that possess enzymatic activity within their cytoplasmic domain, which is activated upon ligand binding.

Receptors Associated with Cytosolic Enzymes

Receptors that, upon ligand binding, activate an associated cytosolic enzyme to initiate a signaling cascade.

Receptor Tyrosine Kinase (RTK)

A type of receptor that, when activated, phosphorylates tyrosine residues.

RTK Activation

The process by which RTKs activate; upon ligand binding, RTK monomers dimerize, leading to cross-phosphorylation and full activation of the receptor.

SH2 Domain

A protein domain that recognizes and binds to phosphorylated tyrosine residues, facilitating protein interactions and downstream signaling.

RAS Proteins

Monomeric proteins that bind to guanine nucleotides (GTP or GDP), acting as molecular switches in signaling pathways; GTP-bound form is active, while GDP-bound form is inactive.

RASGEF/SOS

A protein that facilitates the exchange of GDP for GTP on Ras proteins, activating them.

MAP Kinase Pathway

A series of kinases that sequentially activate each other, transmitting signals from the cell surface to the nucleus and influencing various cellular processes.

Receptor-Mediated Endocytosis

A mechanism for bringing an activated receptor, along with its ligand, to another location in the cell, such as transporting nerve growth factor to the soma of a neuron.

RASGAP

Proteins that inactivate Ras proteins by stimulating GTP hydrolysis, converting them to their inactive GDP-bound state.