Your GPU needs to be of the speed of a GTX550/Radeon HD7770 or higher. Use a speed comparison website like GPUBoss's gaming bar to give you an idea as you will have to worry more about shader processing power than GB's of RAM onboard. You will be running at absolute lowest settings to fit the graphics on your small GPU RAM though, but can get it running pretty smoothly. Your CPU is fine, but you will want to upgrade your RAM to 6GB to be able to load into matches reliably whilst online, otherwise RAM thrashing will cause you to timeout and disconnect often. That is absolute lowest, and I have experimented a lot with playing GTA as my partner wanted to play in the house with me, but on a media server with a 2.4Ghz Q6600 quad.
All this are rumours because i have a core 2 quad q9550 , 4gb ddr3 ram and a 512mb hd 5450 and i am capable to run gta v on normal settings without lags and with a stable fps of 25 -30 frames
* if it would be possible for me i will upload a video on YouTube for you my friend
No, "All this are not rumors". It's just me and everyone else posting know that MB/GB RAM size of your GPU is not relevant to performance. There are several dozen different models of 1GB card that are slower than several dozen other 512MB cards, and even then the OP never specified if this was dedicated GDR RAM like you have 512MB of, or shared system RAM allocation, which often can go up to 1.5GB in size, yet a 1.5GB shared DDR GPU will have circles run around it by even 256MB of dedicated GDDR.