NEW YORK — Sarah Jessica Parker has endorsed her “Sex and the City” castmate Cynthia Nixon’s run for governor of New York.

Parker endorsed Nixon on Instagram on Thursday, calling her “my sister on and off screen.”

Nixon is challenging incumbent Gov. Andrew Cuomo for the Democratic nomination.

Nixon has been active on issues including LGBT rights and public education funding. She has called Cuomo “Andrew the bully” and accused him of giving “massive tax breaks to corporations.”

Cuomo’s campaign has pointed to his achievements, including legalizing gay marriage, tightening gun restrictions and raising the state’s minimum wage.

“Sex and the City” star Kristin Davis also has endorsed Nixon.

The three women plus Kim Cattrall starred in the HBO show from 1998 to 2004 and in two subsequent “Sex and the City” films.