Towards defining receptors for L-tyrosine and L-dopa

We postulate that in mammalian systems neurotransmitter and hormone-like functions of L-tyrosine (LT) and L-DOPA (LD) are mediated via specific membrane-bound and/or nuclear receptors. The structure and function of these receptors may represent an evolutionary continuum of regulatory proteins binding LT or LD in unicellular and lower multicellular organisms.