My name is Qing Fan.
I'm from Colombia University.
The research in my lab involves
the structural studies of class C G-protein coupled receptors.
GPCRs are divided into different classes
based on the sequence homology of their trans-membrane domains.
Most GPCRs such as rhodopsin and Beta-2 adrenergic receptor belong to class A.
These receptors contain a seven helix trans-membrane domain and can function as monomers.
The ligand binding site of
the class A receptors is located within the trans-membrane domain.
Landmark studies led by Dr. Kodaka's group revealed that agonist binding directly
induces conformational changes among the trans-membrane helices for receptor activation.
Class C GPCRs mediate a number of
key biological phenomena including excitatory and inhibitory neurotransmission,
calcium homeostasis, and taste.
Unlike the class A receptors,
the class GPCRs are characterized by a large extracellular domain.
In addition to the canonical seven helix trans-membrane domain,
this extracellular domain is 500-600 amino
acids long and contains the orthosteric ligand binding site.
Another unique feature of
the class C receptors is that they require dimerization for function.
While metabotropic glutamate receptors and calcium sensing
receptor function as disulfide-linked homodimers,
GABA B receptor and taste receptors are obligatory heterodimers.
Our goal is to use structural methods to probe
the signal transduction mechanisms of class C receptors and GPCR dimers in general.
Specifically, we're focusing on human GABA B receptor and human calcium sensing receptor.