Faculty Collaboration Database

Localization of N-terminal sequences in human AMP deaminase isoforms that influence contractile protein binding. Biochem Biophys Res Commun 2001 Jul 13;285(2):489-95

Date

07/11/2001

Pubmed ID

11444869

DOI

10.1006/bbrc.2001.5180

Scopus ID

2-s2.0-0034816639 (requires institutional sign-in at Scopus site)   22 Citations

Abstract

The reversible association of AMP deaminase (AMPD, EC 3.5.4.6) with elements of the contractile apparatus is an identified mechanism of enzyme regulation in mammalian skeletal muscle. All three members of the human AMPD multigene family contain coding information for polypeptides with divergent N-terminal and conserved C-terminal domains. In this study, serial N-terminal deletion mutants of up to 111 (AMPD1), 214 (AMPD2), and 126 (AMPD3) residues have been constructed without significant alteration of catalytic function or protein solubility. The entire sets of active enzymes are used to extend our understanding of the contractile protein binding of AMPD. Analysis of the most truncated active enzymes demonstrates that all three isoforms can associate with skeletal muscle actomyosin and suggests that a primary binding domain is located within the C-terminal 635-640 residues of each polypeptide. However, discrete stretches of N-terminal sequence alter this behavior. Residues 54-83 in the AMPD1 polypeptide contribute to a high actomyosin binding capacity of both isoform M spliceoforms, although the exon 2- enzyme exhibits significantly greater association compared to its exon 2+ counterpart. Conversely, residues 129-183 in the AMPD2 polypeptide reduce actomyosin binding of isoform L. In addition, residues 1-48 in the AMPD3 polypeptide dramatically suppress contractile protein binding of isoform E, thus allowing this enzyme to participate in other intracellular interactions.

Author List

Mahnke-Zizelman DK, Sabina RL

Author

Donna K. Mahnke Research Scientist I in the Pediatrics department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

AMP Deaminase
Amino Acid Sequence
Animals
Binding Sites
Cell Line
Contractile Proteins
Humans
Introns
Isoenzymes
Kinetics
Molecular Sequence Data
Myosins
Recombinant Proteins
Reverse Transcriptase Polymerase Chain Reaction
Sequence Alignment
Sequence Deletion
Sequence Homology, Amino Acid
Spodoptera
Transfection