Revised genomic structure of the human MAGP1 gene and identification of alternate transcripts in human and mouse tissues.
The human MAGP1 (or MFAP2) and mouse Magp1 genes code for the microfibril-associated glycoprotein-1 (MAGP-1), an extracellular matrix protein of microfibrillar structures. We report a revised 5' genomic structure including the use of a single transcription start site that gives rise to a 32-bp 5' exon spanning a segment of the previously described exon B. No evidence of heterogeneous 5' ends from the use of alternative promoters was found in human tissues and cell lines. We located the genetic marker D1S170 to a position 3 kb downstream of the polyadenylation site. Large-scale comparison of the human and mouse genes revealed conservation of sequence outside the coding exons. Although the 5' flanking regions were found to be divergent certain cis-elements for transcription factors are conserved, including Sp1, AP-2, AP-4, NF-kappaB, and c-ETS motifs. We identified a total of five splice variants in addition to the canonical MAGP1A/Magp1A form. These transcripts are species-specific and are generated by different processing mechanisms. The alternate forms MAGP1A', MAGP1B, and MAGP1C are expressed in human tissues; and the two variants Magp1A" and Magp1D were found only in mouse. The alternatively spliced forms show restricted patterns of expression relative to the canonical isoform.
Segade
F
F
Department of Cell Biology and Physiology, Washington University School of Medicine, St. Louis, MO 63110, USA. fsegade@cellbio.wustl.edu
Broekelmann
T J
TJ
Pierce
R A
RA
Mecham
R P
RP
D020121:5' Untranslated Regions; D017398:Alternative Splicing; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D003001:Cloning, Molecular; D003285:Contractile Proteins / Q000235:genetics*; D018076:DNA, Complementary; D016326:Extracellular Matrix Proteins / Q000235:genetics*; D005819:Genetic Markers; D014644:Genetic Variation; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D000072260:RNA Splicing Factors; D012333:RNA, Messenger; D017422:Sequence Analysis, DNA; D014158:Transcription, Genetic
D020121:5' Untranslated Regions; D003285:Contractile Proteins; D018076:DNA, Complementary; D016326:Extracellular Matrix Proteins; D005819:Genetic Markers; D000072260:RNA Splicing Factors; D012333:RNA, Messenger; C016598:microfibrillar protein