Amy Doyle is exiting her post as general manager of MTV, VH1 and other ViacomCBS cable networks.

Doyle had been with Viacom since 1999 and had become a key lieutenant of Chris McCarthy, head of ViacomCBS’ Entertainment and Youth unit that houses MTV, VH1, Comedy Central, Paramount Network and other cable brands and production units. Doyle most recently served as g.m. of MTV, VH1, CMT and Logo.

ViacomCBS is in the midst of layoffs and restructuring following the merger of Viacom and CBS Corp. in December, but Doyle’s decision to move on was her own. McCarthy announced her departure Tuesday in a memo to staffers. Doyle will leave the company in the spring after a transition period.

“During her long and successful tenure, she will leave a legacy of building incredible teams, championing talent and creating some of the most memorable moments in pop-culture history,” McCarthy wrote. “She is a huge champion of our brands, our social impact work and each of you — she has helped shape the heart and soul of the company and for that we thank her dearly.”

Doyle previously headed MTV’s music group and was known for her work in shepherding projects with such stars as Beyoncé, Adele, Camila Cabello, P!nk, Queen Latifah, Florence and the Machine, Tiffany Haddish, Rebel Wilson and Chelsea Handler. She was also co-chair of MTV’s Save the Music Foundation that helped supported music programs in public schools.

Doyle also previously served as an executive producer of MTV Movie Awards and MTV Video Music Awards.