TY - JOUR

T1 - Adrm1, a putative cell adhesion regulating protein, is a novel proteasome-associated factor.

AU - Jørgensen, Jakob Ploug

AU - Lauridsen, Anne-Marie

AU - Kristensen, Poul

AU - Dissing, Karen

AU - Johnsen, Anders H

AU - Hendil, Klavs B

AU - Hartmann-Petersen, Rasmus

N1 - Keywords: Amino Acid Sequence; Animals; Cell Adhesion; Cytoplasm; Electrophoresis, Gel, Two-Dimensional; Glycosylation; Hela Cells; Humans; Intracellular Membranes; Membrane Glycoproteins; Mice; Molecular Sequence Data; Organ Specificity; Proteasome Endopeptidase Complex; Protein Binding; Sequence Homology, Amino Acid

PY - 2006

Y1 - 2006

N2 - We have identified Adrm1 as a novel component of the regulatory ATPase complex of the 26 S proteasome: Adrm1 was precipitated with an antibody to proteasomes and vice versa. Adrm1 co-migrated with proteasomes on gel-filtration chromatography and non-denaturing polyacrylamide gel electrophoresis. Adrm1 has been described as an interferon-gamma-inducible, heavily glycosylated membrane protein of 110 kDa. However, we found Adrm1 in mouse tissues only as a 42 kDa peptide, corresponding to the mass of the non-glycosylated peptide chain, and it could not be induced in HeLa cells with interferon. Adrm1 was present almost exclusively in soluble 26 S proteasomes, albeit a small fraction was membrane-associated, like proteasomes. Adrm1 was found in cells in amounts equimolar with S6a, a 26 S proteasome subunit. HeLa cells contain no pool of free Adrm1 but recombinant Adrm1 could bind to pre-existing 26 S proteasomes in cell extracts. Adrm1 may be distantly related to the yeast proteasome subunit Rpn13, mutants of which are reported to display no obvious phenotype. Accordingly, knock-down of Adrm1 in HeLa cells had no effect on the amount of proteasomes, or on degradation of bulk cell protein, or accumulation of polyubiquitinylated proteins. This indicates that Adrm1 has a specialised role in proteasome function.

AB - We have identified Adrm1 as a novel component of the regulatory ATPase complex of the 26 S proteasome: Adrm1 was precipitated with an antibody to proteasomes and vice versa. Adrm1 co-migrated with proteasomes on gel-filtration chromatography and non-denaturing polyacrylamide gel electrophoresis. Adrm1 has been described as an interferon-gamma-inducible, heavily glycosylated membrane protein of 110 kDa. However, we found Adrm1 in mouse tissues only as a 42 kDa peptide, corresponding to the mass of the non-glycosylated peptide chain, and it could not be induced in HeLa cells with interferon. Adrm1 was present almost exclusively in soluble 26 S proteasomes, albeit a small fraction was membrane-associated, like proteasomes. Adrm1 was found in cells in amounts equimolar with S6a, a 26 S proteasome subunit. HeLa cells contain no pool of free Adrm1 but recombinant Adrm1 could bind to pre-existing 26 S proteasomes in cell extracts. Adrm1 may be distantly related to the yeast proteasome subunit Rpn13, mutants of which are reported to display no obvious phenotype. Accordingly, knock-down of Adrm1 in HeLa cells had no effect on the amount of proteasomes, or on degradation of bulk cell protein, or accumulation of polyubiquitinylated proteins. This indicates that Adrm1 has a specialised role in proteasome function.

U2 - 10.1016/j.jmb.2006.06.011

DO - 10.1016/j.jmb.2006.06.011

M3 - Journal article

C2 - 16815440

VL - 360

SP - 1043

EP - 1052

JO - Journal of Molecular Biology

JF - Journal of Molecular Biology

SN - 0022-2836

IS - 5

ER -