Abstract: Cell-associated secretion-enhancing fusion proteins are disclosed that comprise a target protein binding domain and a transmembrane retention domain. Co-expression in a host cell of a fusion protein and a target protein of interest that is temporarily bound by the fusion protein leads to an increased level of target protein secreted from the host cell. The fusion proteins are engineered to be retained with the producing host cell, thus eliminating a non-natural component from the extracellular media of the host cell and simplifying purification of the target protein. Nucleic acid molecules encoding such fusion proteins are also disclosed for use in expressing the fusion proteins in host cells, for use in restoring lost or diminished cell functions, and for use in treating diseases characterized by a lost or diminished cell function. Methods and compositions comprising fusion proteins of the invention are disclosed for use in enhancing the level of co-expressed target proteins secreted from host cells.

Abstract: Fusion proteins comprising a protein expression enhancing polypeptide linked to a target protein binding domain and nucleic acid molecules encoding such fusion proteins are described for use in enhancing expression and/or location of a targeted protein of interest, for restoring lost functions in cells, and for treating disease. Additional fusion proteins comprising a target protein of interest modified with a fusion partner comprising a protein expression enhancing polypeptide are also disclosed.