Alternative protein secretion: the Mam1 ABC transporter supports secretion of M-factor linked GFP in fission yeast.
To examine whether the fission yeast Mam1 ABC transporter can be used for secretion of heterologous proteins, thereby bypassing the classical secretion pathway, we have analyzed chimeric forms of the M-factor precursor. It was demonstrated that GFP can be exported when fused to both the amino-terminal prosequence from mfm1 and a CaaX motif. This secretion was dependent on the Mam1 transporter and not the classical secretion pathway. The secretion efficiency of GFP, however, was relatively low and most of the reporter protein was trapped in the vacuolar membranes. Our findings suggest that the Mam1 ABC protein is a promiscuous peptide transporter that can accommodate globular proteins of a relatively large size. Furthermore, our results help in defining the sequences required for processing and secretion of natural M-factor.
Kjaerulff
Søren
S
Pharmexa A/S, Kogle Allé 6, DK-2970 Hørsholm, Denmark. sku@my.molbio.ku.dk
Müller
Sven
S
Jensen
Martin Roland
MR
D018528:ATP-Binding Cassette Transporters / Q000502:physiology*; D000595:Amino Acid Sequence; D049452:Green Fluorescent Proteins / Q000378:metabolism*; D036341:Intercellular Signaling Peptides and Proteins; D008969:Molecular Sequence Data; D010455:Peptides / Q000378:metabolism*; D011498:Protein Precursors / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012568:Schizosaccharomyces / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000378:metabolism* / Q000502:physiology*; D016415:Sequence Alignment
D018528:ATP-Binding Cassette Transporters; D036341:Intercellular Signaling Peptides and Proteins; D010455:Peptides; D011498:Protein Precursors; D011993:Recombinant Fusion Proteins; D029702:Schizosaccharomyces pombe Proteins; C107004:mam1 protein, S pombe; C490320:mfm1 protein, S pombe; D049452:Green Fluorescent Proteins