YAMAMOTO Hiroyuki, Ph.D. / Associate Professor

Division of Microbiology and Molecular Cell Biology

Department of Pharmaceutical Sciences

Research Topics

1. Activation mechanisms of neuropeptides in non-endocrine tissue.

2. Identification of novel bioactive peptides cleaved from precursor proteins.

3. Isolation of novel prohormone convertases involving in the extracellular processing.

Our research questions center on the post-translational modification of neuropeptides produced in the peripheral tissue.
Neuropeptides are usually matured by specific proteolytic cleavages of their precursor proteins in the intracellular. We have found that some non-endocrine cells release bioactive peptides as precursors, and would like to determine how these precursors are converted to active forms in the extracellular milieu. We are interested in the mechanism of bioactive peptide processing in peripheral tissues and in carcinoma. We are now attempting to find the novel bioactive peptides in the secretion of the neuropeptides after UV-irradiation and during inflammation.

Representative Publications

1. Yamamoto H., Sawaguchi Y., Kimura M., The determination of protease specificity in mouse tissue extracts by MALDITOF mass spectrometry: manipulating pH to cause specificity change, Journal of Visualized Experiments, 135, e57469, doi:10.3791/57469 (2018).

2. Yamamoto, H., Okada, R., Tanaka, R., Unno, K., Iguchi, K.; Expression of a urokinase-type plasminogen activator during tumor growth leads to angiogenesis via galanin activation in tumor-bearing mice. FEBS Open Bio, 7, 1784-1792 (2017).

3. Yamamoto, H., Ramos-Molina, B., Lick, A.N., Prideaux, M., Albornoz, V., Bonewald, L., and Lindberg, I.; Posttranslational processing of FGF23 in osteocytes during the osteoblast to osteocyte transition. Bone, 84, 120-130 (2016).

4. Yamamoto, H., Yamane, T., Iguchi, K., Tanaka, K., Iddamalgoda, A., Unno, K., Hoshino, M., Takeda, A. Melanin production through novel processing of proopiomelanocortin in the extracellular compartment of the auricular skin of C57BL/6 mice after UV-irradiation. Sci. Rep. 5, 14579 (2015).