Early MTV veejay John "J.J." Jackson died of an apparent heart attack Wednesday in Los Angeles. He was 62. "He was a big part of the channel's success and we are sure he is in the music section of heaven, with lots of his friends and heroes," MTV said in a statement. "He will be greatly missed." After leaving the music network in 1986, Jackson returned to his radio roots, hosting a nationally syndicated show on the Westwood One Radio Network. Most recently, he hosted an afternoon slot on Los Angeles' KTWV.