Lysosomal alpha-mannosidases of mouse tissues: characteristics of the isoenzymes, and cloning and expression of a full-length cDNA

Biochem J. 1997 Oct 1;327 ( Pt 1)(Pt 1):45-9. doi: 10.1042/bj3270045.

Abstract

Lysosomal alpha-d-mannosidase from mouse tissues was separated into its constituent isoenzymes by DEAE-cellulose chromatography. Forms corresponding to the human isoenzymes B and A were present in testis, brain, spleen and kidney, whereas in epididymis and liver only the B form was present. Murine alpha-mannosidases A and B are glycoproteins and have pH optima, thermal stabilities and molecular masses similar to those of the human isoenzymes. A full-length cDNA (3.1 kb) containing the complete coding sequence for alpha-mannosidase was isolated from a mouse macrophage cDNA library. Comparison of the deduced amino acid sequences of human and mouse alpha-mannosidases showed that they had 75% identity and 83% similarity. Expression of this cDNA in COS cells showed that both the A and the B isoenzymes can arise from a single transcript. Northern blotting analysis showed a 10-fold range in the abundance of alpha-mannosidase mRNA in mouse tissues, with the highest levels found in epididymis, and the lowest in liver.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Blotting, Northern
  • COS Cells
  • Chromatography, DEAE-Cellulose
  • Chromosome Mapping
  • Cloning, Molecular
  • DNA, Complementary / genetics
  • Gene Expression
  • Humans
  • Isoenzymes / chemistry*
  • Isoenzymes / genetics
  • Isoenzymes / isolation & purification
  • Isoenzymes / metabolism
  • Lysosomes / enzymology*
  • Mannosidases / chemistry*
  • Mannosidases / genetics*
  • Mannosidases / isolation & purification
  • Mannosidases / metabolism
  • Mice
  • Molecular Sequence Data
  • RNA, Messenger / genetics
  • RNA, Messenger / metabolism
  • Sequence Homology, Amino Acid
  • alpha-Mannosidase

Substances

  • DNA, Complementary
  • Isoenzymes
  • RNA, Messenger
  • Mannosidases
  • alpha-Mannosidase

Associated data

  • GENBANK/U29947