question: List scaffold proteins of the ERK signaling pathway.
answer: Originally identified in yeast, scaffold proteins are now recognized to contribute to the specificity of MEK/ERK pathways in mammalian cells. These scaffolds include kinase suppressor of Ras (KSR), beta-arrestin, MEK partner-1 (MP-1), Sef and IQ motif-containing GTPase-activating protein 1(IQGAP1). Human disc-large homolog (hDlg) acts as a MEK2-specific scaffold protein for the ERK signaling pathway. Two scaffold proteins, caveolin-1 and IQGAP1, are required for phosphorylation of the actin associated pool of extracellular signal regulated kinase 1 and 2 (ERK1/2). Several 14-3-3 isotypes bind to protein kinase C (PKC)-zeta and facilitate coupling of PKC-zeta to Raf-1 an event that boosts the mitogen-activated protein kinase (ERK) pathway.