cellular communication & signaling

Signal transduction pathway

The process by which a signal on a cell's surface is converted into a specific cellular response.

Gap junctions

direct cytoplasmic connections between adjacent cells

Plasmodesmata

direct cytoplasmic connection in adjacent plant cells

Endocrine Signaling

long range peptide or steroid hormones that are delivered through the circulatory system

Hormones

chemical signal

Paracrine signaling

short range proteins released by neighboring cells

Autocrine signaling

secreted molecules diffuse locally and trigger a response in the cells that secrete them

Neuronal signaling

short range neurotransmitters release into synapses between cells in the nervous system

Juxtacrine signaling

transmembrane protein signaling between two neighboring cells in physical contact

Contact dependent signaling

two cells must be in contact to transmit a signal, signals may be passed through a dela and notch on the outside of cells

Reception

the signal is bound by a receptor then relayed into the cytoplasm

Transduction

a signal transduction pathway relays the signal into the cell

Response

cellular responses are activated in both the cytoplasm and nucleus to respond to the signal

Receptors

span the membrane and relay the signal to a signal transduction pathway inthe cell

Signal transduction cascade

a series of steps by which a signal on a cells surface is converted into a specific cellular response

Kinase

an enzyme that catalyzes the transfer of a phosphate group from ATP to a specified molecule.

Phosphatase

removes a phosphate group from a molecule

Molecular switches

activated by phosphorylation of GDP binding as a result of a signal to the cell

Phosphorylation cascade

sequential activation of a series of kinases that amplifies the signal

Phosphodiesterase

enzyme that degrades cAMP, producing AMP, to terminate signaling

Ion channel-linked receptor

Transmembrane protein that opens and closes in response to the binding of specific ligands; allows passage of specific ion types across a cell membrane.

G-protein coupled receptor

a subunit binds to GTP, the B complex is released and activated, leads to target protein activation

Adenylyl cyclase

produces cAMP

cAMP

a second messenger hat amplifies a signal

EGF

epidermal growth factor

Receptor Tryosine Kinase

phosphorylation cascade that leads to gene activation

Ras

activates signal transduction phosphorylation cascade, activated by nucleotide exchange

MAP kinase cascade

Mitogen Activated Protein kinase cascade, changes protein activity and gene expression