If your PD is current before your PERM get approved from your current company, you can submit I-485 for approved I-140 by yourself but you have to get the supporting letter from previous company, plus the job letter from current company.
If your PD is current before your PERM get approved from your current company, you can submit I-485 for approved I-140 by yourself but you have to get the supporting letter from previous company, plus the job letter from current company.