国外大学细胞生物学课件-英文--、18.bioy120111071009_1062850f4

• Receptor tyrosine kinases - have intrinsickinase activity; phosphorylate specific tyrosine (Y) residues on a small set of intracellular signaling proteins.
D103 - Cell Biology - lecture 18
© 2011 Grant MacGregor & Christine Sü tterlin - all rights reserved
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Cell Surface Receptors with Intrinsic or Associated Enzyme Activity
intrinsic or associated kinase activity, plus their downstream effectors -
Receptor
Transduction signaling proteins
• TGFb-family receptors Smads
• Cytokine receptors
• Receptor guanylylcyclases - directly catalyze synthesis of cGMP in cytosol.
sixteen classes of receptors with discrete mechanisms of signal transduction
• The enzyme is often a kinase (or phosphatase) with specificity for a tyrosine, serine or threonine amino acid.
D103 - Cell Biology - lecture 18
© 2011 Grant MacGregor & Christine Sü tterlin - all rights reserved
Page 1
There are five major classes of enzyme-linked cell surface receptors
• The cytoplasmic domain of an enzyme-linked cell surface receptor can have either intrinsic enzyme activity, or may be physically associated with an enzyme.
ຫໍສະໝຸດ Baidu
D103 - Cell Biology - lecture 18
© 2011 Grant MacGregor & Christine Sü tterlin - all rights reserved
Page 2
Cell Surface Receptors with Intrinsic or Associated Kinase Activity
Lecture 18 – Signaling V Cell Surface Receptors with Intrinsic or Associated Kinase Activity
• General background on cell surface receptors with intrinsic or associated kinase activity. • Examples of different ways in which cell surface transmembrane receptors can be activated. • Illustration of principles - three different classes of cell surface receptors that have either
• Tyrosine-kinase associated receptors - these cell surface receptors don't have intrinsic kinase activity, but instead they associate with proteins that have such activity.
• Receptor serine / threonine kinases - have intrinsic kinase activity; phosphorylate specific serine (S) or threonine (T) residues on intracellular signaling proteins.
JAK's / STAT's
• Receptor tyrosine kinasesRas / MAP kinase
• Examples of diseases associated with defects in these pathways.
Recommended Reading: MBOC 5e, pages 921 - 945
• ‘Receptor-like’ tyrosine phosphatases - remove phosphate groups from tyrosines. Termed ‘receptor-like’ because no ligand has to date been found for these proteins.
• As with GPCR, enzyme-linked cell surface receptors are transmembrane proteins, with a ligand-binding domain onthe outside of the cell.
• Unlike GPCR, enzyme-linked cell surface receptors are usually single-pass transmembrane proteins.