Mammalian cells contain a second nucleocytoplasmic hexosaminidase

Martin Gutternigg , Dubravko Rendić , Regina Voglauer , Thomas Iskratsch , Iain Wilson (1)

1 Department fuer Chemie

Some thirty years ago, work on mammalian tissues suggested the presence of two cytosolic hexosaminidases in mammalian cells; one of these has been more recently characterised in recombinant form and has an important role in cellular function due to its ability to cleave β-N-acetylglucosamine residues from a variety of nuclear and cytoplasmic proteins. However, the molecular nature of the second cytosolic hexosaminidase, named hexosaminidase D, has remained obscure. In the present study, we molecularly characterise for the first time the human and murine recombinant forms of enzymes, encoded by HEXDC genes, which appear to correspond to hexosaminidase D in terms of substrate specificity, pH dependency and temperature stability; furthermore, a myc-tagged form of this novel hexosaminidase displays a nucleocytoplasmic localisation. Transcripts of the corresponding gene are expressed in a number of murine tissues. Based on its sequence, this enzyme represents, along with the lysosomal hexosaminidase subunits encoded by the HEXA and HEXB genes, the third class 20 glycosidase to be found from mammalian sources.

Mots clés: Life Sciences

Martin Gutternigg, Dubravko Rendić, Regina Voglauer, Thomas Iskratsch, Iain Wilson. Mammalian cells contain a second nucleocytoplasmic hexosaminidase. Biochemical Journal, 2009, 419 (1), pp.83-90. ⟨10.1042/BJ20081630⟩. ⟨hal-00479082⟩