Mario Etheridge, 28, of Detroit, is charged in the shooting with carrying a concealed weapon and discharge of a firearm in a building. His lawyer entered not guilty pleas on his behalf at Saturday's hearing.
Etheridge was arraigned via video by Magistrate Steve Lockhart in 36th District Court in Detroit. Bond was set at $70,000 and a preliminary hearing in the case was scheduled for April 26.
The Wayne County prosecutor's office said that without the weapons charges, which were issued Friday, authorities would have had to release Etheridge. The shooting remains under investigation.
Etheridge has been in custody since he surrendered Wednesday; his lawyer has said the shooting was in self-defense.
"If it wasn't for Proof trying to harm someone, we wouldn't be here today," said Etheridge's lawyer, Randall Upshaw.
Detroit police said they were told by witnesses that Etheridge shot Proof early Tuesday after Proof shot Army veteran Keith Bender inside a nightclub in a strip of businesses along Eight Mile Road.
The thoroughfare, which divides Detroit and its northern suburbs, was made famous in the 2002 film "8 Mile," which starred Eminem.
Bender remained in critical condition Saturday a St. John Hospital and Medical Center, said hospital spokeswoman Wende Berry.
Proof, 32, whose real name was Deshaun Holton, was a member of the rap group D12 and was the best man in Eminem's January wedding. His funeral was scheduled for Wednesday, with public viewing Tuesday.
Proof's lawyer has said that the police investigation will clear the rapper's name.
If convicted, Etheridge faces a maximum of five years in prison on the concealed weapon charge and four years on the discharging a firearm count.