Yaqub, who starred in Ken Loach's film Ae Fond Kiss, will feature in the second series of the show, which charts the lives of a group of 20-something women from Glasgow's gay scene.
The stylish bars, clubs and streets of the Merchant City area featured heavily in the first series, which stars Glasgow actress Laura Fraser.
Yaqub is one of several new faces to join the BBC3 drama.
The first episode of the show was seen by 600,000 viewers and attracted a dedicated following of tens of thousands of fans on Facebook and Twitter, the internet social networking sites.
However, the show also sparked a wave of viewer complaints over its lesbian sex scenes.
Ruta Gedmintas will return as photographer Frankie in the new series, with Laura Fraser as architect Cat and Fiona Button as accident-prone actress Tess.
A new face, Anna Skellern, will play a straight-talking Australian doctor who is turning heads and attracting attention.
The familiar lads from the first series, James Anthony Pearson as author Ed and Emun Elliott as bad boy Jay, are joined by Adam Sinclair (Irvine Welsh's Ecstasy) as irreverent doctor, Declan Love.
Writer Harriet Braun said: "I'm delighted this second series has given me a chance to develop more compelling stories for our characters, as well as mixing things up with some new and intriguing faces."
Derek Wax, executive producer, said: "The world and characters Harriet created captured people's imaginations in a way we could not have anticipated.
"It is so exciting to be back in Glasgow working with her, our tremendous cast and such an amazing Scottish team on the second series."