BIOL 2021 Lecture Notes - Lecture 14: Mitosis, Rate Limiting, Cell Cortex
12 May 2013
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Document Summary
Protein tyrosine phosphatases remove phosphates from tyrosines. Time + place of action can be regulated. Ligands= extracellular proteins (called transforming growth factor-beta, tgf-beta) Receptors are similar to rtks as they are both transmembrane proteins in plasma membrane. Dimeric ligand will bring together receptors--> smad protein. Figure 15-69: receptors are heterodimers (different from each other) They transphosphorylate each other which activates them. Activated receptor has kinase activity and will phosphorylate smad proteins. Will enter nucleus and affect gene transcription, important to development and tissue repair etc. Quick route to nucleus (not as quick as a nuclear receptor, but very quick for an extracellular protein) Cells integrate and compute information (they get signals from many sources and will have to decide what to do) Quantitative interactions between signals not just qualitative on/off response. We can use computer models to understand cells. Actual receptor does not have kinase activity, but it will activate one downstream.
