The Sec20/Tip20p complex is involved in ER retrieval of dilysine-tagged proteins.
Sec20p and Tip20p were previously identified as two interacting proteins involved in early steps of the secretory pathway in Saccharomyces cerevisiae. Here we describe a novel temperature-sensitive allele of TIP20 and analyze its phenotype. While sec20 and tip20 mutants exhibited a defect in forward ER-to-Golgi transport at the non-permissive temperature, both were also defective for retrieval of various dilysine-tagged proteins from the Golgi back to the endoplasmic reticulum (ER) at lower temperature. Dilysine-dependent Golgi localization of Emp47p was also defective in both mutants. These results suggest a role for the Sec20/Tip20p complex in retrieval of dilysine-tagged proteins back to the ER.
Cosson
P
P
Basel Institute for Immunology, Switzerland.
Schröder-Köhne
S
S
Sweet
D S
DS
Démollière
C
C
Hennecke
S
S
Frigerio
G
G
Letourneur
F
F
D000483:Alleles; D001693:Biological Transport, Active / Q000235:genetics; D002352:Carrier Proteins; D004151:Dipeptides / Q000737:chemistry; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D005656:Fungal Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006023:Glycoproteins; D006056:Golgi Apparatus / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D010641:Phenotype; D050766:Qb-SNARE Proteins; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D033921:Vesicular Transport Proteins
D002352:Carrier Proteins; D004151:Dipeptides; D005656:Fungal Proteins; D006023:Glycoproteins; D008562:Membrane Glycoproteins; D050766:Qb-SNARE Proteins; C073173:SEC20 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; C489479:TIP20 protein, S cerevisiae; D033921:Vesicular Transport Proteins; C024575:lysyllysine