A polypeptide having an amino acid sequence corresponding to a binding domain of a botulinum toxin is described. The polypeptide modulates expression of genes involved in, for example, collagen production and extra cellular matrix organization, and finds use, therefore in modulating skin quality attributes such as elasticity, firmness etc. Moreover, the polypeptide inhibits lipogenesis in specialized cells and finds use, therefore, in reducing skin oiliness, which is frequently observed in skin tissue afflicted with large pores and acne. Nucleic acids encoding the polypeptide, as well as vectors, host cells, and systems comprising the nucleic acids, are further described.