Intro to Cell Signaling Flashcards
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PLX
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How do cells process information?
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the role of the cell signaling systems is to receive input from the environment and, on the basis of that input, generate an appropriate output response -
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Cells able to sense
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What are some various inputs involved in cell signaling?
- environmental stresses
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What are some of the various outputs involved in cell signaling?
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Feedback
Sometimes outputs interact in feedback mechanism to affect inputs
how so?
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What are three examples of extracellular signaling?
- autocrine signaling
- paracrine signaling
- endocrine signaling
autocrine
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paracrine signaling
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endocrine signaling
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Give examples of each:
1 - autocrine signaling
2 - paracrine signaling
3 - endocrine signaling
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Changes may be extracellular or intracellular.
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What is signal transduction?
includes the mechanism by which inputs are sensed and how recognition of input produce specific rapid cellular responses
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What are some characteristics of cell signaling?
- enables transmission from outside of cell to nucleus
- fast ON and OFF (seconds to minutes)
- transient changes (minutes to hours)
- spatial/directional responses and organization
- energetically cheap (no protein synthesis; maybe just a few ATP used)
What are some characteristics of gene expression?
- slow ON and OFF (minutes to hours)
- stable changes (hours to years)
- limited spatial responses
- energetically costly (transcription and translation)
What are some advantages of cell signaling?
quick, energetically cheap
What is the general scheme of signal transduction?
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When/how is signal transduction initiated?
signal transduction is initiated upon recognition of the input (stimulus) by its receptor
By what are receptors classified?
- according to their cellular localization
- shared mechanism of action
What are four classifications of receptors (these aren’t the only ones)?
- cell surface receptors
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What are the four types of cell surface receptors (there are more than these)?
1 - Ligated-ion channels
2 - G-protein coupled receptors (GPCRs) (vision, taste smell, neurotransmitter release, etc)
3 - Receptor protein kinases
4 - Protein kinase-associated receptors
What are the different types of intracellular receptors?
1 - Nuclear Receptors (NR)
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Nuclear Receptors (NR)
- a superfamily of receptor (~48 members in the human genome)
- NRs have
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Toll-like Receptors (TLRs) and NOD-like receptors
can be found in cytoplasm or embedded in …
- bind ligand in intracellular compartments (endosomes) or the cytoplasm
- these receptors bind viral nucleic acids and bacterial cell wall components and induce transcription of pro-inflammatory
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Intracellular ligand-gated ion channels
- found inside cells (as well as…something previously)
- PIP2 is embedded in plasma membrane; cleaved by phospholipase C..blah blah
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Recognition of the external stimulus by the receptor provides the first message in signal transduction
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