Jim Trimmer


Position Title
Distinguished Professor

Department of Physiology and Membrane Biology, School of Medicine


Research Interests

Cell signaling in mammalian neurons, neuronal cell biology, membrane protein trafficking and function, affinity reagent development and validation

Grad Group Affiliations

  • Biochemistry, Molecular, Cellular and Developmental Biology
  • Molecular, Cellular and Integrative Physiology

Specialties / Focus

  • Cell Biology
  • Neurobiology
  • Tool development
  • Proteomics


  • NPB 107 Cell Signaling in Health and Disease, Winter


  • 4103/4107 Tupper Hall
    • Elijah Blank (junior specialist, PREP@UCD scholar), Rebecca Boulden (undergraduate student), Karen Cornejo (undergraduate student, UCLEADS scholar), Jie-Xian Dong (postdoc), Camelia Dumitras (staff research associate), Belvin Gong (staff research associate), Ting Gong (BMCDB graduate student), Karl Murray (assistant adjunct professor), Deborah van der List (staff research associate),  Nick Vierra (postdoc, NRSA fellow)

Honors and Awards

  • 2000-2007 Jacob Javits Neuroscience Investigator (MERIT) Award, National Institute of Neurological Disorders and Stroke, National Institutes of Health
  • 1994-1999 Established Investigatorship, American Heart Association

    Professional Societies

    • Society for Neuroscience
    • American Society for Cell Biology


    • 1987 PhD (Marine Biology) University of California, San Diego/Scripps Inst. Oceanography
    • 1981 BA (Biology) University of California, San Diego


    Zheng, Y., Liu, P., Bai, L., Trimmer, J. S., Bean, B. P., and D. D. Ginty. (2019). Deep Sequencing of Somatosensory Neurons Reveals Molecular Determinants of Intrinsic Physiological Properties. Neuron 103:598-616.

    Andrews, N. P., Boeckman, J. X., Manning, C. F., Nguyen, J. T., Bechtold, H., Dumitras, C., Gong, B., Nguyen, K., van der List, D., Murray, K. D., Engebrecht, J. and J. S. Trimmer. (2019). A Toolbox of IgG Subclass-Switched Recombinant Monoclonal Antibodies for Enhanced Multiplex Immunolabeling of Brain. eLife 8:e43322.

    Kirmiz, M., Palacio, S., Thapa, P., King, A. N., Sack, J. T. and J. S. Trimmer. (2018). Remodeling Neuronal ER-PM Junctions is a Conserved Nonconducting Function of Kv2 Plasma Membrane Ion Channels. Mol. Biol. Cell 29: 2410-2432.

    Kirmiz, M., Vierra, N. C., Palacio, S., and J. S. Trimmer. (2018). Identification of VAPA and VAPB as Kv2 Channel-Interacting Proteins Defining Endoplasmic Reticulum-Plasma Membrane Junctions in Mammalian Brain Neurons. J. Neurosci. 38: 7562-7584.

    Taussig, M. J., Fonseca, C., and J. S. Trimmer. (2018). Antibody Validation: A View from the Mountains. New Biotech. 45:1-8.

    Baba, K., Yoshida, W., Toriyama, M., Shimada, T., Manning, C. F., Kohno, K., Trimmer, J. S., Watanabe, R., and N. Inagaki. (2018). Gradient-Reading and Mechano-Effector Machinery for Netrin-1–Induced Axon Guidance. eLife 7. pii: e34593.

    Simhal, A. K., Gong, B., Trimmer, J. S., Weinberg, R. J., J. Smith, S. J., Sapiro, G., and K. D. Micheva. (2018). Automated Antibody Characterization and Screening for Array Tomography via Probabilistic Synapse Detection. Front. Neuroanat. 12:51.

    Bradbury, A. R. M., Trinklein, N. D., Thie, H., Wilkinson, I. C., Tandon, A. K., Anderson, S., Bladen, C. L., Jones, S., Force Aldred, S., Bestagno, M., Burrone, O., Maynard, J., Ferrara, F., Trimmer, J. S., Görnemann, J., Glanville, J., Wolf, P., Frenzel, A., Wong. J., Yu, X., Eng, H.-Y., Lane, D, Lefranc, M.-P., Clark, M., & Dübel, S. (2018). When Monoclonal Antibodies are not Monospecific: Hybridomas Frequently Express Additional Functional Variable Regions. mAbs 27:1-19.

    Riquelme, D., Silva, I., Philp, A. M., Huidobro-Toro, J. P., Cerda, O., Trimmer J. S., and E. Leiva-Salcedo. (2018). Subcellular Localization and Activity of TRPM4 in Medial Prefrontal Cortex Layer 2/3. Front. Cell. Neurosci. 12: 12.

    Bishop, H. I., Cobb, M. M., Kirmiz, M., Parajuli, L., Mandikian, D., Philp, A. M., Melnik, M., Kuja-Panula, J., Rauvala, H., Shigemoto, R., Murray, K. D., and J. S. Trimmer. (2018). Kv2 Channels Determine the Expression and Localization of the Associated AMIGO-1 Cell Adhesion Molecule in Adult Brain Neurons. Front. Mol. Neurosci. 11: 1.

    Jensen, C. S., Watanabe, S., Stas, J. I., Klaphaak, J., Schmitt, N., Olesen, S.-P., Trimmer, J. S., Rasmussen, H. B., and H. Misonou. (2017). Trafficking of Kv2.1 Channels to the Axon Initial Segment by a Novel Non-Conventional Secretory Pathway. J. Neurosci. 37:11523-11536.

    Speca, D. J., Trimmer, J. S., Peterson, A. S., and E. Diaz. (2017). Whole Exome Sequencing Reveals a Functional Mutation in the GAIN Domain of the Bai2 Receptor Underlying a Forward Mutagenesis Hyperactivity QTL. Mammalian Genome 28:465-475. 

    Palacio, S., Chevaleyre, V., Brann, D. H., Murray, K. D., Piskorowski, R. A., and J. S. Trimmer. (2017). Heterogeneity in Kv2 Channel Expression Shapes Action Potential Characteristics and Firing Patterns in CA1 Versus CA2 Hippocampal Pyramidal Neurons eNeuro 4(4).

    Gong, B., Murray, K. D., and J. S. Trimmer. (2016). Developing High-Quality Mouse Monoclonal Antibodies for Neuroscience Research – Approaches, Perspectives and Opportunities. New Biotech. 33: 551-564.

    Kirk, L. M., Ti, S. W., Bishop, H. I., Llamas-Orozco, M., Pham, M., Trimmer, J. S., and E. Diaz. (2016). Distribution of the SynDIG4/Proline Rich Transmembrane Protein 1 in Rat Brain. J. Comp. Neurol524:2266-2280.

    Cobb, M. M., Austin, D. C., Sack, J. T., and J. S. Trimmer. (2015). Cell Cycle-Dependent Changes in Localization and Phosphorylation of the Plasma Membrane Kv2.1 K+ Channel Impact Endoplasmic Reticulum Membrane Contact Sites in COS-1 Cells. J. Biol. Chem. 290:29189-29201.

    Bishop, H. I., Guan, D., Bocksteins, E., Parajuli, L., Murray, K. D., Cobb, M. M., Misonou, H., Zito, K., Foehring, R. C., and J. S. Trimmer. (2015). Distinct Cell- and Layer-Specific Expression Patterns and Independent Regulation of Kv2 Channel Subtypes in Cortical Pyramidal Neurons. J. Neurosci. 35:14922-14942.

    Thiffault, I., Speca, D. J., Austin, D. C., Cobb, M. M., Eum, K. S., Safina, N. P., Grote, L., Farrow, E. G., Miller, N., Soden, S., Kingsmore, S. F., Trimmer, J. S., Saunders, C. J., and J. T. Sack. (2015) A Novel Epileptic Encephalopathy Mutation in KCNB1 Disrupts Kv2.1 Ion Selectivity, Expression, and Localization. J. Gen. Physiol. 146:399-410.

    Cerda, O., Leiva-Salcedo, E., Park, K.-S., Cáceres, M., Romeroa, A., Varela, D., Trimmer, J. S., and A. Stutzinband. (2015). Casein Kinase-Mediated Phosphorylation of Serine 839 Is Necessary for Basolateral Localization of the Ca2+-Activated Non-Selective Cation Channel TRPM4. Pflugers Arch. 467: 1723-1732.

    Jan, L. Y., Attali, B., Nerbonne, J., Sanguinetti, M. C., Trimmer, J. S.,  Chandy, K. G., Grissmer, S., Gutman, G. A., Lazdunski, M., Mckinnon, D., Pardo, L. A., Robertson, G. A., Rudy, B., Stühmer, W., and X. Wang. (2015). Voltage-Gated Potassium Channels. IUPHAR/BPS Guide to PHARMACOLOGY,  http://www.guidetopharmacology.org/GRAC/FamilyDisplayForward?familyId=81.

    Cáceres, M., Ortiz, L., Romero, A., Recabarren, T., Colombo, A., Leiva-Salcedo, E., Varela, D., Rivas, J., Silva, I., Campusano, C., Almarza, O., Simón, F., Toledo, H., Park, K.-S., Trimmer, J. S., and O. Cerda. (2015). TRPM4 is a Novel Component of the Adhesome Required for Focal Adhesion Disassembly, Migration and Contractility. PLoS ONE 10:e0130540. 

    Hirono, M., Ogawa, Y., Misono, K., Zollinger, D. R., Trimmer, J. S., Rasband, M. N., and H. Misonou. (2015). BK Channels Localize to the Paranodal Junction and Regulate Action Potentials in Myelinated Axons of Cerebellar Purkinje Cells. J. Neurosci. 35:7082-7094.

    Trimmer, J. S., and H. Misonou. (2015). Ion Channel Phosphorylation. (Chapter 36, pages 531-544). In The Handbook of Ion Channels. (J. Zheng and M. C. Trudeau, Editors). CRC Press, Boca Raton, FL.

    Hsiao, J. J., Ng, B. H., Smits, M. M., Wang, J., Jasavala, R. J., Martinez, H. D., Lee, J. A., Alston, J. J., Misonou, H., Trimmer, J. S., and M. E. Wright. (2015). Androgen Receptor and Chemokine Receptors 4 and 7 Form a Signaling Axis to Regulate CXCL12-Dependent Cellular Motility. BMC Cancer 15:204. 

    Trimmer, J. S. (2015). Subcellular Localization of K+ Channels in Mammalian Brain Neurons: Remarkable Precision in the Midst of Extraordinary Complexity. Neuron 85: 238-256.

    For a complete list of publications see: http://www.ncbi.nlm.nih.gov/pubmed/?term=trimmer+js