Welcome to the Ryo Lab

Human Immunodeficiency Virus type 1 (HIV-1) infection is an agent of Acquired Immunodeficiency Syndromes (AIDS). The infection of HIV-1 comprises of multistep and multifactorial processes mediated by a complex series of virus-host cell interactions.  The molecular interactions between host cell factors and HIV-1 are vital to our understanding of not only the nature of the resulting viral replication, but also the subsequent cytopathogenesis in the infected cells.  Our research purpose is to identify host proteins and signaling mechanisms that regulate HIV replication and pathogenesis. These new findings could therefore provide a further elucidation of virus-host cell interactions and identify putative molecular targets for the HIV-1 replication pathway. The following is a list of the ongoing research projects in our laboratory.

Identification of host proteins that regulate HIV-1 replication and pathogenesis.

• Proteomics analysis of HIV-1 proteins.
• Development of gene therapy for HIV/AIDS with pluripotent stem cells.
• Development of a new drug-screening system in the use of cell-free protein production system.

Prolyl isomerase Pin1: a novel post-phosphorylation mechanism twisting in cancer and neurodegenerative diseases

Phosphorylation of proteins on serine or threonine residues preceding proline (Ser/Thr-Pro) is a major intracellular signaling mechanism. The peptidyl-prolyl cis/trans isomerase (PPIase). Pin1 binds only to phospho-Ser/Thr-Pro motifs on its substrate proteins, thereby catalyzing the cis/trans isomerization of the peptide bond and acting as a post phosphorylation catalyst in the regulation of protein function.

This "post-phosphorylation" isomerization can lead to conformational changes in the substrate proteins and modulate their functions. Consequently, Pin1 has been shown to be involved in the regulation of many cellular events, including proliferation and differentiation, and has been involved in the genesis of cancer and neurodegenerative diseases. We are interested in how Pin1-mediated "post-phosphorylation" modification triggers the cellular signaling mechanism, and how its deregulation causes the diseases.