Lysyl oxidase and P-ATPase-7A expression during embryonic development in the rat.
Lysyl oxidase activity is critical for the assembly and cross-linking of extracellular matrix proteins, such as collagen and elastin. Moreover, lysyl oxidase activity is sensitive to changes in copper status and genetic perturbations in copper transport, e.g., mutations in the P-type ATPase gene, ATP7A, associated with cellular copper transport. Lysyl oxidase may also serve as a vehicle for copper transport from extracellular matrix cells. Herein, we demonstrate that sufficient lysyl oxidase functional activity is present in the rat embryo at gestation day (GD) 9 to be detected in conventional enzyme assays. Estimation of embryonic lysyl oxidase functional activity, however, required partial purification in order to remove inhibitors. From GD 9 to GD 15, lysyl oxidase activity was relatively constant when expressed per unit of protein or DNA. In contrast, the steady-state levels of lysyl oxidase and ATP7A mRNA, measured by RT-PCR and expressed relative to total RNA and cyclophilin mRNA, increased approximately fourfold from GD 9 to 15. The pattern of temporal expression for ATP7A was consistent with its possible role in copper delivery to lysyl oxidase.
Tchaparian
E H
EH
Department of Nutrition, Department of Food Science and Technology, University of California, One Shields Avenue, Davis, California 95616-8669, USA.
Uriu-Adams
J Y
JY
Keen
C L
CL
Mitchell
A E
AE
Rucker
R B
RB
D000251:Adenosine Triphosphatases / Q000235:genetics*; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000235:genetics*; D027682:Cation Transport Proteins; D003300:Copper / Q000378:metabolism; D000073840:Copper-Transporting ATPases; D004622:Embryo, Mammalian / Q000201:enzymology*; D005314:Embryonic and Fetal Development; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic; D005865:Gestational Age; D019696:Peptidylprolyl Isomerase / Q000235:genetics; D008249:Protein-Lysine 6-Oxidase / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D011993:Recombinant Fusion Proteins; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
D002352:Carrier Proteins; D027682:Cation Transport Proteins; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D003300:Copper; D008249:Protein-Lysine 6-Oxidase; D000251:Adenosine Triphosphatases; D019696:Peptidylprolyl Isomerase; C486202:Atp7a protein, rat; D000073840:Copper-Transporting ATPases