Juliana Popova, PhD Physiology and Biophysics Research Assistant Professor

My research program is focused on the interrelationship between phospholipase signaling and the dynamics of the microtubule cytoskeleton.  Phospholipase signaling is triggered by agonist-activated membrane receptors and regulates a plethora of intracellular events through generation of the second and third messengers inositol trisphosphate (IP3), diacylglycerol (DAG) and calcium.  We have demonstrated that when specific receptors are activated, the microtubule protein, tubulin, is involved in the regulation of phospholipase Cb1 (PLCb1) signal transduction.  Tubulin appears to regulate PLCb1 through consecutive, direct interactions with the a subunit of the PLCb1 regulatory G protein, Gq, and Gbg subunits.  In turn certain Ga and Gbg subunits regulate microtubule assembly.  Our present studies aim to answer the following major questions: Which are the molecular events involved in the translocation of tubulin to, and from, the plasma membrane during phospholipase signaling?  Which are the interfaces of tubulin, Gaq and Gbg interactions and how are these interactions regulated? and, How does phospholipase signaling affect the microtubule cytoskeleton, cell structure and shape?  We employ diverse experimental techniques from the fields of cellular and molecular biology, biochemistry and pharmacology to dissect the molecular events involved at different steps of this complex intracellular crossregulation.  We hope that our studies will help to better understand fundamental cellular functions, such as division, growth and differentiation, transformation, secretion, motility and change in cell shape. 

Recent Publications: 

1.  Popova JS, Greene A,Wang J, Rasenick MM. Phospatidylinositol 4,5-bisphosphate modifies tubulin participation in PLCb1 signaling. J. Neurosci. 22:1668-1667, 2002.

2.  Yan K, Popova JS, Moss A, Shah B, Rasenick MM. Tubulin stimulates adenylyl cyclase activity in C6 glioma cells by bypassing the b-adrenergic receptor: A potential mechanism of G protein activation. J. Neurochem. 76:182-190, 2001.

3.  Popova J, Rasenick MM. Muscarinic receptor activation promotes membrane association of tubulin for the regulation of Gq-mediated phospholipase Cb1 signaling. J. Neurosci. 20:2774-2782, 2000.

4.    Popova JS, Garrison JC, Rhee S-G, Rasenick MM. Tubulin, Gq and phosphatidylinositol 4,5-bisphosphate interact to regulate phospholipase Cb1 signaling. J. Biol. Chem. 272:6760-6765, 1997.

5.  Popova J, Dubocovich ML. Melatonin receptor-mediated stimulation of phosphoinositide breakdown in chick brain slices. J. Neurochem. 64:130-138, 1995.

6.  Popova, J, Johnson GL, Rasenick MM. Chimeric Gas/Gai2 proteins define domains on Gas which interact with tubulin for the b-adrenergic activation of adenylyl cyclase. J. Biol. Chem. 269:21748-21754, 1994.

Send message to:  jsp@uic.edu