Melissa Johnson (Cavallin), Ph.D.

Professor & Undergraduate Program Coordinator
School of Field Investigations and Experimental Sciences Dr. Perry College of Mathematics, Computing, and Sciences

678-839-4043
mcavalli@wei0Tsvb7qwlhTpARh1mhstga.edu

Biology Building - Room 207
Office Hours
Fall 2024 (In-Person) Office Hours:
Mondays & Wednesdays 11am-1pm
Tuesdays 9-11am
Thursdays & Fridays by appointment only

Virtual Office Hours offered Monday-Friday by appointment only. Email me at mcavalli@westga.edu to set up an appointment.

Download curriculum vitae for Melissa Johnson (Cavallin), Ph.D. in PDF
Melissa Johnson (Cavallin), Ph.D.

Research Interests:

My research interest is exploring the intercellular and intracellular signaling cascades involved in the chemical senses (taste and smell).  I am interested in understanding how ion channels are regulated and how this affects downstream signaling molecules.  A voltage-gated potassium channel (Kv1.3) is important for regulating the firing of action potentials in mitral cell neurons of the olfactory bulb.  The mitral cell neuron is the primary output neuron of the olfactory bulb that transmits olfactory information to the brain.  Altering the activity of Kv1.3 will ultimately change how the brain perceives olfactory sensory information, or in other words, how the brain determines what odors you smell in the air.  Tyrosine kinases are enzymes that add a phosphate group to the amino acid tyrosine in proteins.  Phosphorylating Kv1.3 closes the channel and decreases K+ current flowing out of the mitral cell.  This means that the mitral cell is more excitable because the resting membrane potential is less negative.  I am interested in exploring the modulation of Kv1.3 by the tyrosine phosphatases SHP-2 & PTP-1b and the dual-specific phosphatase MKP-1, enzymes that remove phosphate groups from tyrosines and/or serines in proteins.  This reverse reaction may also be important in regulating the firing of action potentials by mitral cell neurons because it would increase K+ current flowing out of the mitral cell making the mitral cell less excitable.  Patch-clamp electrophysiology, protein biochemistry, and histology are just a few of the techniques that will be utilized to understand phosphatase regulation of Kv1.3.

Selected Grants and Awards:

  1. AREA R15 Application (NIH). Grant Number: 1R15DC011923. Phosphatase regulation of olfactory bulb mitral cell activity. (2011-2014).
  2. Faculty Research Grant Program (UWG), MKP-1 regulation of olfactory system function (2015-2016).
  3. Student Research Assistant Program (UWG), Phosphatase expression in the Olfactory Epithelium and Olfactory Bulb (2010-2013).
  4. COSM Research Initiative Award (UWG), Phosphatase expression in the Olfactory Bulb and Olfactory Epithelium (2011-2012).
  • B.A., Biology with Chemistry Minor, LaGrange College, 2002
  • Ph.D., Physiology, Medical College of Georgia, 2007

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Odor enrichment sculpts the abundance of olfactory bulb mitral cells

State-dependent sculpting of olfactory sensory neurons is attributed to sensory enrichment, odor deprivation, and aging

The olfactory bulb: a metabolic sensor of brain insulin and glucose concentrations via a voltage-gated potassium channel

Brain-derived neurotrophic factor modulation of Kv1.3 channel is disregulated by adaptor proteins Grb10 and nShc

Awake intranasal insulin delivery modifies protein complexes and alters memory, anxiety, and olfactory behaviors