Structure, chromosomal localization, and promoter analysis of the human elastin microfibril interfase located proteIN (EMILIN) gene.
Elastin microfibril interfase-located protein (EMILIN) is an extracellular matrix glycoprotein abundantly expressed in elastin-rich tissues such as the blood vessels, skin, heart, and lung. It occurs with elastic fibers at the interface between amorphous elastin and microfibrils. In vitro experiments suggested a role for EMILIN in the process of elastin deposition. This multimodular protein consists of 995 amino acids; the domain organization includes a C1q-like globular domain at the C terminus, a short collagenous stalk, a region containing two leucine zippers, and at least four heptad repeats with a high potential for forming coiled-coil alpha-helices and, at the N terminus, a cysteine-rich sequence characterized by a partial epidermal growth factor-like motif and homologous to a region of multimerin. Here we report the complete characterization of the human and murine EMILIN gene, their chromosomal assignment, and preliminary functional data of the human promoter. A cDNA probe corresponding to the C terminus of EMILIN was used to isolate two genomic clones from a human BAC library. Sequencing of several derived subclones allowed the characterization of the whole gene that was found to be about 8 kilobases in size and to contain 8 exons and 7 introns. The internal exons range in size from 17 base pairs to 1929 base pairs. All internal intron/exon junctions are defined by canonical splice donor and acceptor sites, and the different domains potentially involved in the formation of a coiled-coil structure are clustered in the largest exon. The 3'-end of the EMILIN gene overlaps with the 5'-end of the promoter region of the ketohexokinase gene, whose chromosomal position is between markers D2S305 and D2S165 on chromosome 2. A 1600-base pair-long sequence upstream of the translation starting point was evaluated for its promoter activity; five deletion constructs were assayed after transfection in primary chicken fibroblasts and in a human rhabdomyosarcoma cell line. This analysis indicates the existence of two contiguous regions able to modulate luciferase expression in both cell types used, one with a strong activatory function, ranging from positions -204 to -503, and the other, ranging from positions -504 to -683, with a strong inhibitory function.
Doliana
R
R
Divisione di Oncologia Sperimentale 2, Centro di Riferimento Oncologico, 33081 Aviano, Italy.
Canton
A
A
Bucciotti
F
F
Mongiat
M
M
Bonaldo
P
P
Colombatti
A
A
D020121:5' Untranslated Regions; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D002889:Chromosomes, Human, Pair 2; D015922:Complement C1q / Q000737:chemistry; D005091:Exons; D016326:Extracellular Matrix Proteins / Q000235:genetics; D005819:Genetic Markers; D006801:Humans; D007438:Introns; D008156:Luciferases / Q000096:biosynthesis / Q000235:genetics; D008562:Membrane Glycoproteins / Q000235:genetics*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012326:RNA Splicing; D017384:Sequence Deletion
D020121:5' Untranslated Regions; D016326:Extracellular Matrix Proteins; D005819:Genetic Markers; D008562:Membrane Glycoproteins; C030340:elastin microfibril interface located protein; D015922:Complement C1q; D008156:Luciferases