Figure 1.

(A) Positively charged Protamine spontaneously assembles with negatively charged nucleic acids (here mRNA), formulating nanocomplexes; (B) The Protamine-RNA complex is internalized into the cell via endosomes. RNA acts as danger signals that trigger TLR7/8 to stimulate innate immune responses (see paragraph 3). mRNA released into the cytoplasm is translated into the desired protein (see paragraph 2); (C) Amino acid sequence of salmon sperm-derived protamine. Nuclear localization signal (NLS) highlighted in red [13].