Cloning and tissue distribution of rat heart fatty acid binding protein mRNA: identical forms in heart and skeletal muscle.
A fatty acid binding protein (FABP) has been identified and characterized in rat heart, but the function and regulation of this protein are unclear. In this study the cDNA for rat heart FABP was cloned from a lambda gt11 library. Sequencing of the cDNA showed an open reading frame coding for a protein with 133 amino acids and a calculated size of 14776 daltons. Several differences were found between the sequence determined from the cDNA and that reported previously by protein sequencing techniques. Northern blot analysis using rat heart FABP cDNA as a probe established the presence of an abundant mRNA in rat heart about 0.85 kilobases in length. This mRNA was detected, but was not abundant, in fetal heart tissue. Tissue distribution studies showed a similar mRNA species in red, but not white, skeletal muscle. In general, the mRNA tissue distribution was similar to that of the protein detected by Western immunoblot analysis, suggesting that heart FABP expression may be regulated at the transcriptional level. S1 nuclease mapping studies confirmed that the mRNA hybridized to rat heart FABP cDNA was identical in heart and red skeletal muscle throughout the entire open reading frame. The structural differences between heart FABP and other members of this multigene family may be related to the functional requirements of oxidative muscle for fatty acids as a fuel source.
Department of Biochemistry, Boston University School of Medicine, Massachusetts 02118.
K P
KP
Claffey
V L
VL
Herrera
P
P
Brecher
N
N
Ruiz-Opazo
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002352:Carrier Proteins / Q000235:genetics*; D003001:Cloning, Molecular; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism*; D005796:Genes; D008969:Molecular Sequence Data; D009132:Muscles / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism*; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009693:Nucleic Acid Hybridization; D009928:Organ Specificity; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics*; D051381:Rats
D002352:Carrier Proteins; C490174:Fabp7 protein, rat; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D012333:RNA, Messenger