UCL Division of Biosciences


Annette C Dolphin Group

My group has expertise in the field of neuronal voltage-dependent calcium channels, and our current work has particular reference to the role of accessory subunits, beta and alpha2delta. We are examining how these subunits modulate the channels and how these interactions are affected in disease states or by drugs.

Current projects

Some specific current projects include:

  • Regulation of alpha2delta subunit processing, expression and trafficking under normal and pathological conditions, including neuropathic pain.
  • Mechanism of action of gabapentin and related drugs, that bind to alpha2delta subunits. ia.
  • Calcium channel trafficking in neurons and role of the beta subunit.
  • Mechanism of dominant negative suppression of expression by truncated calcium channel alpha1-subunits such as those resulting from episodic ataxia-2 mutations.

Keywords: Calcium, Ion channels, G-protein coupled receptors, Neuron, Pain, Epilepsy, Pharmacology, Protein misfolding

Conditions: Ataxias, Epilepsy , Pain - chronic, neuropathic

Methods: Electrophysiological recording techniques, fluorescence microscopy techniques, gene expression profiling - tissue level, image analysis, immunohistochemistry, light microscopic techniques, live cell imaging, patch-clamp recording, protein purification, proteomics, cell culture.

Our research

My group is currently working on the relationship between the molecular and biophysical properties of voltage-dependent calcium channels and their physiological roles.

We are using a number of different techniques to tackle these problems: heterologous expression of siRNA in cell lines with or without endogenous channels, biophysical studies of macroscopic currents, together with site-directed mutagenesis and chimeric channel production. We have made a number of antibodies to calcium channels which are being used for studies of the molecular epitopes controlling the selective trafficking of different subtypes of calcium channels.

We are also using fusion proteins and epitope-tagged proteins and domains for the biochemical study of calcium channel domain interactions using surface plasmon resonance studies. The yeast two hybrid technique is being used to identify novel interactions involved in trafficking and processing of different subtypes of calcium channels.

1. Sites of interaction between alpha1 and beta subunits of calcium channels using tagged channels and loops.

sites of interaction

2. Mechanism of action of alpha2delta subunits to traffic calcium channels, and the mechanism of action of the drug gabapentin on calcium channel trafficking both in vitro and in vivo.

Mechanism of action of alpha2delta subunits to traffic calcium channels

3. Consequences of the mutation in the alpha-2 delta2 subunit in the mouse mutant Ducky that has absence epilepsy and cerebellar ataxia.

4. Mechanism of dominant negative suppression of expression by truncated calcium channel alpha1 subunits, and relationship to episodic ataxia-2

5. Mechanisms of G protein modulation of calcium channels

6. Consequences of novel neuronal calcium channel stargazin-like (gamma7) subunit expression

View all publications

Main research contributions

For many years, one of my main areas of interest has been in the properties of neuronal calcium channels and their modulation by G proteins, and the relationship of this to presynaptic inhibition of transmitter release. My group was the first to show that presynaptic inhibition by agents such as adenosine involves a pertussis toxin sensitive GTP binding protein (Prestwich and Dolphin, 1985), and was among the first to show that activation of such G proteins results in inhibition of calcium currents, and this can be mimicked by the G protein activator GTPgS (Scott and Dolphin, 1996, 1987). 

More recently we have been investigating the mechanism of G protein inhibition of calcium currents, and were the first to show that the intracellular calcium channel b subunit interacts with modulation by G proteins (Campbell et al 1995).

Most recently we have shown that voltage-dependent G protein modulation by Gbg is lost in the absence of a calcium channel b subunit (Meir et al 2000). We have identified a 11 amino acid motif on the intracellular N terminus of the a1B calcium channel that is essential for its G protein modulation (Page et al., 1998, Canti et al., 1999), and are currently examining how this domain exerts its function.

Group members

Research fellows and assistants

  • Karen Page PhD: Studies on the mechanism of action of the calcium channel β subunits.
  • Manuela Nieto-Rostro PhD: α2δ subunit function and properties of knockout mice
  • Wojciech Margas PhD:  Electrophysiological studies on calcium channel assembly
  • Marianna D’Arco PhD: Studies on calcium channel α2δ subunits in sensory neurons
  • Shehrazade Dahimène PhD:  Mechanism of dominant-negative suppression in episodic ataxia-2 
  • Wendy Pratt: Molecular biology and laboratory manager. Studies on calcium channel splice variant expression
  • Kanchen Chaggar: tissue culture and biochemistry

PhD students

  • John Cassidy: Calcium channel trafficking
  • Natsuko Macabuag: Trafficking of calcium channel splice variants