Experiment

Observation results of the Protein Crystal Growth Experiment conducted onboard "Kibo" (Flash report)

On June 2, the protein crystal samples acquired in the High-Quality Protein Crystal Growth Experiment (the sixth session of the second series) conducted onboard the Japanese Experiment Module ("Kibo") from April 21 of this year returned to Earth. Microscopic observation was conducted on June 6, immediately after the samples were returned to Japan from Russia, in order to grasp the conditions of crystal growth in space. Part of the observation is introduced here as a flash report.

The protein crystals acquired that will be handed to researchers are to be subjected to analysis using radiation facilities including SPring-8 and the Photon Factory.

See below for information regarding the start of the experiment.

Protein Crystal Growth Experiment (the sixth session of the second series) started

Content

1. Clarification of high-resolution crystal structure of F-actin
2. Ultra-high resolution crystal structure analysis of complex of intracellular domain of CD28 family receptors and signal transduction proteins

Clarification of high-resolution crystal structure of F-actin

Principal investigator: Yuichiro Maeda, Senior Research Fellow, Graduate School of Science, Nagoya University

【Outline of the theme】

The research group led by Senior Research Fellow Yuichiro Maeda aims to analyze the high resolution crystal structure of actin, a protein that plays an important role in diverse vital phenomena including cell movement, muscle contraction, and cell division, and to clarify its response mechanism.

Microscopic observation has revealed that good-quality crystals were produced in this space experiment (shown in the photo below). The group will further aim to clarify its three-dimensional structure in detail.

This research theme targets one of the critical unsolved issues related to vital function. When the three-dimensional structure is clarified in detail from high-quality crystals acquired in this experiment, the outcome is expected to make a great contribution to the development of this research.

Crystal of actin acquired in space (Credit: Nagoya University/JAXA)

Ultra-high resolution crystal structure analysis of complex of intracellular domain of CD28 family receptors and signal transduction proteins

Principal Investigator: Masayuki Oda, Associate Professor, Graduate School of Life and Environmental Sciences, Kyoto Prefectural University

【Outline of the theme】

The group led by Associate Professor Masayuki Oda aims to analyze the ultra-high resolution structure of CD28 family molecules and signal transduction proteins that are related to immune response.

It is known that the CD28 family molecules and signal transduction proteins are potential drug targets for autoimmune diseases including rheumatoid arthritis. This space experiment entailed crystallizing the complex of signal transduction proteins Grb2 SH2 and the CD28 peptide.

Microscopic observation has revealed that good-quality crystals were produced in this experiment (shown in the photo below). The group will further aim to clarify its three-dimensional structure in detail.

The outcome of the experiment is expected to provide knowledge that will lead to the development of low molecular formulations that specifically inhibit intracellular signal transduction.

Crystal of Grb2 SH2-CD28 peptide complex acquired in space (Credit: Kyoto Prefectural University/JAXA)

*All times are Japan Standard Time (JST)