The dynamic structure of Rab35 is stabilized in the presence of GTP under physiological conditions

July 30, 2020

Title

The dynamic structure of Rab35 is stabilized in the presence of GTP under physiological conditions

Author

Takuya Murata, Yuka Unno, Mitsunori Fukuda, Naoko Utsunomiya-Tate

Year

2020

Journal

Biochemistry and Biophysics Reports

Abstract

Rab proteins, a family of small guanosine triphosphatases, play key roles in intracellular membrane trafficking and the regulation of various cellular processes. As a Rab isoform, Rab35 is crucial for recycling endosome trafficking, cytokinesis and neurite outgrowth. In this report, we analyzed dynamic structural changes and physicochemical features of Rab35 in response to different external conditions, including temperature, pH, salt concentration and guanosine triphosphate (GTP), by circular dichroism (CD) spectroscopy. CD spectra revealed that the α-helix content of Rab35 varies under different conditions considerably. The addition of GTP increases the α-helix content of Rab35 when the temperature, pH and salt concentration match physiological conditions. The results suggest that the external environment affects the secondary structure of Rab35. In particular, the presence of GTP stabilized the α-helices of Rab35 under physiological conditions. These structural changes may translate to changes in Rab35 function and relate to its role in membrane trafficking.

Instrument

J-1500

Keywords

Circular dichroism, Thermal stability, Chemical stability, Secondary structure, Pharmaceutical, Biochemistry