Einstein in his book. Relativity: The Special snd General Theory.
http://www.ibiblio.org/ebooks/Einstein/Einstein_Relativity.pdf
writes, "the expression for energy" in the form  $\frac{mc^2 +E_0}{\sqrt 1-v^2/c2}$
Where m is the rest mass. $mc^2$ is the "kinetic energy" of the rest mass, at rest.
 $E_0$ is the energy added to the body. (by adding photons, for instance.)
Then the rest mass energy, $mc^2$, and added energy, $E_0$, is divided by $\sqrt 1-v^2/c2$ to account for the energy of the velocity.
And that, i think, produces gravity. That is my expectation. 
Am I right?

I am no expert on this. I welcome criticism of this post.
I think This energy is what is said to curve spacetime, or create gravity.

Relativistic mass, is calculated as $\frac{M_(rest)}{\sqrt 1-v^2/c2}$

I think that relativistic mass is gravitational, as is "aborbed energy".