Expression of two green fluorescent protein variants in citrate-buffered media in Pichia pastoris

2002 ◽  
Vol 311 (2) ◽  
pp. 193-195 ◽  
Author(s):  
Tessa N Campbell ◽  
Francis Y.M Choy
2004 ◽  
Vol 70 (2) ◽  
pp. 961-966 ◽  
Author(s):  
Antje Eiden-Plach ◽  
Tatjana Zagorc ◽  
Tanja Heintel ◽  
Yvonne Carius ◽  
Frank Breinig ◽  
...  

ABSTRACT Besides its importance as model organism in eukaryotic cell biology, yeast species have also developed into an attractive host for the expression, processing, and secretion of recombinant proteins. Here we investigated foreign protein secretion in four distantly related yeasts (Candida glabrata, Pichia pastoris, Saccharomyces cerevisiae, and Schizosaccharomyces pombe) by using green fluorescent protein (GFP) as a reporter and a viral secretion signal sequence derived from the K28 preprotoxin (pptox), the precursor of the yeast K28 virus toxin. In vivo expression of GFP fused to the N-terminal pptox leader sequence and/or expression of the entire pptox gene was driven either from constitutive (PGK1 and TPI1) or from inducible and/or repressible (GAL1, AOX1, and NMT1) yeast promoters. In each case, GFP entered the secretory pathway of the corresponding host cell; confocal fluorescence microscopy as well as sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Western analysis of cell-free culture supernatants confirmed that GFP was efficiently secreted into the culture medium. In addition to the results seen with GFP, the full-length viral pptox was correctly processed in all four yeast genera, leading to the secretion of a biologically active virus toxin. Taken together, our data indicate that the viral K28 pptox signal sequence has the potential for being used as a unique tool in recombinant protein production to ensure efficient protein secretion in yeast.


Biochemistry ◽  
2005 ◽  
Vol 44 (24) ◽  
pp. 8701-8711 ◽  
Author(s):  
Tim B. McAnaney ◽  
Xinghua Shi ◽  
Paul Abbyad ◽  
Henry Jung ◽  
S. James Remington ◽  
...  

Biochemistry ◽  
1999 ◽  
Vol 38 (17) ◽  
pp. 5296-5301 ◽  
Author(s):  
Marc-André Elsliger ◽  
Rebekka M. Wachter ◽  
George T. Hanson ◽  
Karen Kallio ◽  
S. James Remington

2004 ◽  
Vol 84 (4) ◽  
pp. 611-619 ◽  
Author(s):  
C. E. Strauss ◽  
T. A. McAllister ◽  
L. B. Selinger

The effectiveness of cellular encapsulation as a method for delivery of bioactive proteins and limiting amino acids to the small intestine of ruminants was investigated. Intracellular expression of green fluorescent protein variant (GFPuv) in Pichia pastoris was used as a visible marker to assess the cellular integrity of P. pastoris and determine the potential of this approach for protecting recombinant proteins from microbial proteolysis in the rumen. Fluorescent cells were easily identified in the presence of strained ruminal fluid when viewed by epifluorescent microscopy, and intact cells were readily enumerated. Batch cultures with rumen digesta demonstrated that 93, 97 and 25% of P. pastoris cells remained intact after 36 to 48 h of incubation in clarified ruminal fluid, an isolated bacterial fraction, and whole ruminal fluid, respectively. In continuous culture (Rusitec) with a dilution rate of 0.75 d-1, 19% of P. pastoris cells flowed intact from the fermentation vessels. In vitro abomasal simulations demonstrated that 84% of inoculated P. pastoris had lysed within 12 h of incubation, a property that is necessary for the release of encapsulated protein prior to the small intestine. These in vitro studies suggest that P. pastoris may be an effective vehicle for post-ruminal delivery of bioactive proteins in ruminants. Key words: Ruminal escape vehicle, Pichia pastoris, green fluorescent protein, bypass protein


1998 ◽  
Vol 141 (3) ◽  
pp. 625-636 ◽  
Author(s):  
Yasuyoshi Sakai ◽  
Antonius Koller ◽  
Linda K. Rangell ◽  
Gilbert A. Keller ◽  
Suresh Subramani

We used the dye N-(3-triethylammoniumpropyl)-4-(p-diethylaminophenylhexatrienyl) pyridinium dibromide (FM4-64) and a fusion protein, consisting of the green fluorescent protein appended to the peroxisomal targeting signal, Ser-Lys-Leu (SKL), to label the vacuolar membrane and the peroxisomal matrix, respectively, in living Pichia pastoris cells and followed by fluorescence microscopy the morphological and kinetic intermediates in the vacuolar degradation of peroxisomes by microautophagy and macroautophagy. Structures corresponding to the intermediates were also identified by electron microscopy. The kinetics of appearance and disappearance of these intermediates is consistent with a precursor–product relationship between intermediates, which form the basis of a model for microautophagy. Inhibitors affecting different steps of microautophagy did not impair peroxisome delivery to the vacuole via macroautophagy, although inhibition of vacuolar proteases affected the final vacuolar degradation of green fluorescent protein (S65T mutant version [GFP])-SKL via both autophagic pathways. P. pastoris mutants defective in peroxisome microautophagy (pag mutants) were isolated and characterized for the presence or absence of the intermediates. These mutants, comprising 6 complementation groups, support the model for microautophagy. Our studies indicate that the microautophagic degradation of peroxisomes proceeds via specific intermediates, whose generation and/or processing is controlled by PAG gene products, and shed light on the poorly understood phenomenon of peroxisome homeostasis.


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