To be perfectly honest, I would say you need an upgrade for a game such as this but it is possible on this system, but you wouldn't be getting the full potential out of this game! Your CPU is what really kills it for you!
But one thing you must definitely do is upgrade your RAM! GTAV can take about 4GBs alone! I have the game and 12GBs and RAM. About 2GBs used by Windows and background software before startup, but within gameplay my RAM usage goes upto 7-8GBs in all, although this will vary depending what settings you put it at, it is still something you would have to do.