The RMT union members will walk out from 3am on August 19, 26 and 29, and ban overtime for 48 hours from 27 August onward.
The industrial action is in response to a row over cuts, work conditions and safety, with the union claiming some 1,800 members will be involved.
Virgin said its timetable for East Coast trains will be unaffected by the changes the company is making, but will see a single member of customer-facing personnel on each train.
David Horne, managing director for Virgin Trains on the east coast, said: "With our guarantees that there will be no compulsory redundancies, no impact on safety and a full timetable in place during the walk-outs, these strikes will cost RMT members pay for no reason, and we urge the union to rejoin us around the negotiating table."
The company also added that there were no compulsory redundancies as part of the changes, but the RMT has said almost 200 jobs are under threat on the train line, and train guards, station staff and some drivers were set to take part in the walkouts.
RMT General Secretary Mick Cash said: "RMT will not sit back while nearly 200 members' jobs are under threat and while conditions and safety are put at risk by a franchise which is clearly in financial trouble. We will also not tolerate the cavalier attitude to safety that is now on show as the company mobilises its scab army of managers. Our members are being subject to outrageous intimidation and bullying as their trains are commandeered as part of the scabbing process.
"The company have chosen to treat the negotiations as a game thus far, merely going through the motions of pretending they did not yet know what their plans entailed. To behave like that is to treat the union and its members with pure contempt.
Virgin East Coast London St Pancras to Edinburgh trains run through Grantham, Newark, Lincoln, Doncaster