Cloning and characterization of mouse Lmp3 cDNA, encoding a proteasome beta subunit.
We isolated and sequenced a cDNA encoding mouse proteasome subunit LMP3 from a macrophage cDNA library. The gene encodes a 264-amino-acid protein with a calculated molecular mass of 29.11 kDa and an isoelectric point (pI) of 5.44. Comparison of the predicted protein sequence with that of the human and rat homologues, N3, revealed 11 and eight changes, respectively, in the cleaved NH2-terminal presequence of the precursor protein (pre-LMP3), and six and 10 changes, respectively, in the processed product. To corroborate the predicted molecular mass and pI, we analyzed LMP3 by immunoprecipitation with a mAb to human N3 that crossreacts with mouse LMP3. Precursor and processed forms of LMP3 were identified by 2D NEPHGE-PAGE, and their mobilities suggest the Lmp3 clone encodes the entire protein sequence.
Cruz
M
M
Department of Molecular Genetics, Howard Hughes Medical Institute, University of Cincinnati, OH 45267-0524, USA.
Nandi
D
D
Hendil
K B
KB
Monaco
J J
JJ
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular; D003429:Cross Reactions; D003546:Cysteine Endopeptidases / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000235:genetics* / Q000276:immunology / Q000378:metabolism*; D046988:Proteasome Endopeptidase Complex; D011498:Protein Precursors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D011499:Protein Processing, Post-Translational; D051381:Rats; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid
D009097:Multienzyme Complexes; D011498:Protein Precursors; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex