Atlanta rapper and DJ Unk has died ... TMZ has learned.

Unk's wife, Sherkita Long-Platt, posted on Facebook Friday afternoon ... "Please respect me and my family. I just lost my husband and my kids just lost their father. Our life will never be the same. I LOVE YOU ANTHONY FOREVER"

Unk -- legal name Anthony Leonard Platt -- started out in the late 1990s, eventually forming Southern Style DJs with DJ Montay and DJ Jelly, throwing parties around Georgia. Unk got signed to Big Oomp Records in 2000, along with Montay.

Unk's platinum single "Walk It Out" from the 2006 album "Beat'n Down Yo Block!" cracked the top 10 on the Billboard 100, and the track "2 Step" from the same album was certified gold.

He was dealing with unspecified health issues in 2009, affecting his career activity. He released a couple more singles in the following years, and was featured on the 2K Sports NBA 2K9 video game.

Unk was 43.