cell surface hormone receptor plasma membrane is bound.
cell surface hormone receptor plasma membrane is bound.
which type of hormone receptor plasma membrane bound?
cell surface
molecules are delivered from the plasma membrane to early endosomes in endocytic vesicles. molecules can be internalized via receptor-mediated endocytosis in clathrin-coated vesicles. other types of vesicles also form at the plasma membrane for this pathway, including ones utilising caveolin. vesicles also transport molecules directly back to the plasma membrane, but many molecules are transported in vesicles that first fuse with recycling endosomes. molecules following this recycling pathway are concentrated in the tubules of early endosomes. molecules that follow these pathways include the receptors for ldl, the growth factor egf, and the iron transport protein transferrin. internalization of these receptors from the plasma membrane occurs by receptor-mediated endocytosis. ldl is released in endosomes because of the lower ph, and the receptor is recycled to the cell surface. cholesterol is carried in the blood primarily by (ldl), and transport by the ldl receptor is the main mechanism by which cholesterol is taken up by cells. egfrs are activated when egf binds. the activated receptors stimulate their own internalization and degradation in lysosomes. egf remains bound to the egfr once it is endocytosed to endosomes. the activated egfrs stimulate their own ubiquitination, and this directs them to lumenal vesicles (see below) and so they are not recycled to the plasma membrane. this removes the signaling portion of the protein from the cytosol and thus prevents continued stimulation of growth - in cells not stimulated with egf, egfrs have no egf bound to them and therefore recycle if they reach endosomes. transferrin also remains associated with its receptor, but, in the acidic endosome, iron is released from the transferrin, and then the iron-free transferrin (still bound to the transferrin receptor) returns from the early endosome to the cell surface, both directly and via recycling endosomes.
endosome
p42 map kinase -p53 - pancreatic polypeptide - parathyroid hormone receptor - partial pressure - passive transport - pauling scale - pcr - peptide - peptide bond - peptide elongation factor - peptide elongation factor tu - peptide fragment - peptide initiation factor - peptide receptor - peptide termination factor - peripheral membrane protein - pesticide - ph - phage display - pharmaceutical - pharmacist - pharmacology - phenol - phenotype - phenyl group - phenylalanine - philadelphia chromosome - phospholipid - phospholipid bilayer - phosphopeptide - phosphoprotein - phosphorus - phosphorylation - phosphoserine - phosphothreonine - phosphotyrosine - photobiology - photolysis - photophosphorylation - photoreceptor - photorespiration - photosynthesis - photosystem i - photosystem ii - phototransduction - phylogenetics - phylogeny - physical chemistry - physiology - phytohaemagglutinin - pituitary hormone receptor - pituitary hormone-regulating hormone receptor - plant protein - plasma membrane - plasmid - plasmin - plasminogen - platelet glycoprotein gpib-ix complex - platelet membrane glycoprotein - platelet-derived growth factor - platelet-derived growth factor receptor - polymer - polymerase chain reaction - polymerization - polymyxin - polymyxin b - polyomavirus transforming antigen - polypeptide - polysaccharide - porphyrin - posttranslational modification - potassium - potassium channel - potential energy - pregnancy proteins - primary nutritional groups - primary structure - primer - prion - progesterone receptor - prokaryote - prolactin - prolactin receptor - proline - promoter - prostaglandin e receptor - prostaglandin receptor - protein - protein biosynthesis - protein data bank - protein design - protein expression - protein folding - protein isoform - protein nuclear magnetic resonance spectroscopy - protein p16 - protein p34cdc2 - protein precursor - protein structure prediction - protein subunit - protein synthesis - protein targeting - protein translocation - protein-tyrosine kinase - protein-tyrosine-phosphatase - proteinoid - proteomics - protirelin - proto-oncogene - proto-oncogene proteins - proto-oncogene protein c-kit - proto-oncogene proteins c-abl - proto-oncogene proteins c-bcl-2 - proto-oncogene proteins c-fos - proto-oncogene proteins c-jun - proto-oncogene proteins c-mo - proto-oncogene proteins c-myc - proto-oncogene proteins c-raf - proton - proton pump - protozoan proteins - purine - purinergic p1 receptor - purinergic p2 receptor - purinergic receptor - pyridine - pyrimidine - pyruvate - pyruvate oxidation -
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