Expression of fatty acid-binding proteins in the developing mouse mammary gland.
Proteins of 14,000 daltons (SLP-14) were isolated and partially characterized from mouse mammary glands of different developmental stages. The purified proteins were partially sequenced at the amino acid level. The SLP-14 belong to the family of fatty acid-binding (FABP) proteins. The major SLP-14 expressed was a reflection of the differentiation stage of the mammary gland. Within the regions sequenced for each protein, virgin mouse mammary gland (primarily adipocytes) expressed a protein 100% homologous to adipocyte lipid binding protein whereas pregnant and lactating mouse mammary glands expressed a protein highly homologous to mouse heart fatty acid binding protein. In the lactating gland, the isolated protein was 97% identical to the heart FABP over a 98 amino acid stretch. We could not detect the 14Kd protein identified as mammary gland growth inhibitor (MDGI) which is also a member of the FABP family and highly homologous to heart FABP. A rabbit antiserum to the rat mammary SLP-14 recognized the SLP-14 proteins in mouse and rat mammary gland, skeletal muscle and heart, whereas it failed to recognize the SLP-14 in liver, intestine and other organs. These data indicate that the SLP-14 detected in rodent mammary gland is of the fatty acid-binding protein family. On the basis of amino acid sequence, the major form in the differentiated mouse mammary gland is apparently FABP and not MDGI. MDGI may be a protein in low abundance and/or localized to a specific group of mammary epithelial cells.
Bansal
M P
MP
Dept. of Cell Biology, Baylor College of Medicine, Houston, TX 77030.
Medina
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D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism*; D002850:Chromatography, Gel; D002852:Chromatography, Ion Exchange; D015180:Electrophoresis, Gel, Two-Dimensional; D004591:Electrophoresis, Polyacrylamide Gel; D000071438:Fatty Acid-Binding Protein 7; D050556:Fatty Acid-Binding Proteins; D005227:Fatty Acids / Q000378:metabolism; D005260:Female; D007774:Lactation / Q000378:metabolism*; D008321:Mammary Glands, Animal / Q000378:metabolism*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009206:Myocardium / Q000378:metabolism; D009363:Neoplasm Proteins; D009419:Nerve Tissue Proteins; D009928:Organ Specificity; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D012643:Selenium / Q000378:metabolism; D017386:Sequence Homology, Amino Acid
D000906:Antibodies; D002352:Carrier Proteins; C082667:Fabp5 protein, mouse; C086936:Fabp7 protein, mouse; 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; D012643:Selenium