May function as a transcription factor downstream of MPK1 that is subject to activation by the MPK1 mitogen-activated protein kinase pathway. Binds to the DNA sequence 5'-CTA[TA](4)TAG-3'. At least some RML1 target genes are involved in cell wall biosynthesis. Can heterodimerize with SPM1. Interacts with KDX1 and SLT2. Phosphorylated by SLT2. Present with 736 molecules/cell in log phase SD medium. Belongs to the MEF2 family.