Rab14 from Bombyx mori (Lepidoptera: Bombycidae) shows ATPase activity.
Rab GTPases are essential for vesicular transport, whereas adenosine triphosphate (ATP) is the most important and versatile of the activated carriers in the cell. But there are little reports to clarify the connection between ATP and Rab GTPases. A cDNA clone (Rab14) from Bombyx mori was expressed in Escherichia coli as a glutathione S-transferase fusion protein and purified. The protein bound to [(3)H]-GDP and [(35)S]-GTPgammaS. Binding of [(35)S]-GTPgammaS was inhibited by guanosine diphosphate (GDP), guanosine triphosphate (GTP) and ATP. Rab14 showed GTP- and ATP-hydrolysis activity. The Km value of Rab14 for ATP was lower than that for GTP. Human Rab14 also showed an ATPase activity. Furthermore, bound [(3)H]-GDP was exchanged efficiently with GTP and ATP. These results suggest that Rab14 is an ATPase as well as GTPase and gives Rab14 an exciting integrative function between cell metabolic status and membrane trafficking.
Uno
Tomohide
T
Agrobioscience, Graduate School of Agricultural Science, Kobe University, Nada-ku, Hyogo 657-8501, Japan. unotom@kobe-u.ac.jp
Moriwaki
Tsubasa
T
Isoyama
Yuri
Y
Uno
Yuichi
Y
Kanamaru
Kengo
K
Yamagata
Hiroshi
H
Nakamura
Masahiko
M
Takagi
Michihiro
M
D000251:Adenosine Triphosphatases / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D001667:Binding, Competitive; D012831:Bombyx / Q000201:enzymology* / Q000378:metabolism; D016244:Guanosine 5'-O-(3-Thiotriphosphate) / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D006868:Hydrolysis; D019476:Insect Proteins / Q000378:metabolism / Q000502:physiology; D020691:rab GTP-Binding Proteins / Q000378:metabolism / Q000502:physiology*
D019476:Insect Proteins; D016244:Guanosine 5'-O-(3-Thiotriphosphate); D006160:Guanosine Triphosphate; D000251:Adenosine Triphosphatases; D020691:rab GTP-Binding Proteins