Molecular characterization of a novel endonuclease (Xib) and possible involvement in lysosomal glycogen storage disorders.

Abstract

We cloned and partially characterized a human endonuclease (Xib) which shows sequence homologies to pancreatic DNase I but an enzymatic activity closer to DNase II. We report on the structural differences found between Xib and other recently cloned human DNases. Fluores cence microscopy analysis of transiently transfected cells with Xib::pEGFP constructs indicate that the protein is located in the cytoplasm and possibly anchored to a membrane, as deduced from a hydrophobic amino acid stretch present at the C-terminal end. Xib is overexpressed in muscle and cardiac tissues and is alternately spliced in several normal and neoplastic cells. In situ hybridization studies using human cardiac and muscle biopsies indicate accumulation of Xib transcript in the vacuoles of muscle cells from patients affected by vacuolar myopathy as acid maltase deficiency; however, no point mutations were detected in their DNA.

• Authors: G Malferrari, U Mazza, C Tresoldi, E Rovida, M Nissim, M Mirabella, S Servidei, I Biunno
• Journal: Experimental and molecular pathology (Exp Mol Pathol) Vol. 66 Issue 2 Pg. 123-30 (Jun 1999) ISSN: 0014-4800 [Print] Netherlands
• PMID: 10409440 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright 1999 Academic Press.

Chemical References

• Muscle Proteins
• Recombinant Fusion Proteins
• DNASE1L1 protein, human
• Deoxyribonuclease I

Topics

• Amino Acid Sequence
• Blotting, Northern
• Blotting, Western
• Cloning, Molecular
• Deoxyribonuclease I (genetics)
• Glycogen Storage Disease (enzymology, genetics)
• HeLa Cells (enzymology)
• Humans
• In Situ Hybridization
• Lysosomes (enzymology, genetics)
• Molecular Sequence Data
• Muscle Proteins (genetics)
• Muscle, Skeletal (enzymology)
• Myocardium (enzymology)
• Polymerase Chain Reaction
• Recombinant Fusion Proteins (genetics, metabolism)
• Sequence Homology, Amino Acid
• Transfection