Force on an electron is $Fe =eE$
$F_e$ = Force vector acting on the electron
$e$ charge on the electron
Force experienced by proton having same magnitude of change but is of opposite nature,
Force will be in opposite direction to that of force on electron .
(ie) $F_P$(force on proton) = $-F_e$
The electrostatic forces depends only upon the charges and hot on the masses.