Identification of a novel growth factor-responsive gene in vascular smooth muscle cells.
We have employed differential screening of a rat aortic smooth muscle cell cDNA library to isolate a cDNA clone, SM-20, whose nucleotide and deduced amino acid sequences are distinct from those reported previously. SM-20 encodes an mRNA of approximately 2.5-3.0 kilobase pairs which is present at low levels in quiescent vascular smooth muscle cells. SM-20 levels increase within 1 h of treatment with growth agonists (serum, platelet-derived growth factor, angiotensin II), isoproterenol, and forskolin. Cycloheximide induces high levels of SM-20 mRNA and superinduces it in the presence of serum, suggesting that the increase in SM-20 mRNA levels is not dependent on protein synthesis and is part of the primary response to growth agonists. SM-20 is expressed at high levels in tissues and cells derived from muscle (smooth, skeletal, and cardiac) and nerve (brain, PC12 cells) and is not expressed in 3T3 fibroblasts or rat 6 fibroblasts. SM-20 encodes a new member of the immediate early gene family and is unusual in that it is expressed in vascular smooth muscle, but not in fibroblasts.
Wax
S D
SD
Department of Medicine, Mt. Sinai School of Medicine, New York, New York 10029.
Rosenfield
C L
CL
Taubman
M B
MB
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002478:Cells, Cultured; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006133:Growth Substances / Q000502:physiology*; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases; D017874:Immediate-Early Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009131:Muscle, Smooth, Vascular / Q000378:metabolism*; D011393:Procollagen-Proline Dioxygenase; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D006133:Growth Substances; D017874:Immediate-Early Proteins; D012333:RNA, Messenger; D011393:Procollagen-Proline Dioxygenase; C490189:Egln1 protein, mouse; C087100:Egln3 protein, rat; D064799:Hypoxia-Inducible Factor-Proline Dioxygenases