Transcription factor involved in the regulation of root hair development, possibly through auxin signaling. Its endoplasmic reticulum membrane localization is not compatible with its transcription factor activity in the nucleus. May be cleaved to target the nucleus. Its endoplasmic reticulum membrane localization is not compatible with its transcription factor activity in the nucleus. May be cleaved to target the nucleus. A truncated form of MAMYB (amino acids 84 to 309) lacking the 2 transmembrane domains is localized to the nucleus. Induced by auxin. Its endoplasmic reticulum membrane localization is not compatible with its transcription factor activity in the nucleus. May be cleaved to target the nucleus. A truncated form of MAMYB (amino acids 84 to 309) lacking the 2 transmembrane domains is localized to the nucleus.