eukaryotic evolution

STAT3 can be activated by signaling proteins such

as cytokines and growth factors

signaling proteins bind to cell-surface receptors and activate tyrosine kinases, which

subsequently phosphorylate STAT proteins

STAT proteins that are activated (by signaling proteins) accumulate in the nucleus and initiate

transcription, ultimately affect the phenotype of the cell

in response to cytokine stimulation, a kinase mediates tyrosine phosphorylation

activated STAT3s dimerize, translocates to the nucleus, and initiate DNA binding

STAT3 can also be activated by

serine phosphorylation

(serine phosphorylation) some of the STAT3 in a cell localizes to the mitochondria,

STAT3 is a component of complexes I & II in the electron transport chain

serine phosphorylation seems to be integral to

mitochondrial function

brown fat generates heat in a process known as

non-shivering thermogenesis

brown fat cells are filled with fat but, in contrast to

ordinary fat cells, they are packed with mitochondria; brown fat has a rich blood supply

in brown fat cells, mitochondrial respiration is uncoupled from ATP synthesis through the

expression of uncoupling proteins; energy is dissipated as heat instead of being used to generate ATP

pNaKtide is a

peptide that binds to the Na/K-ATPase and blocks Src activation