MID2, a homologue of the Opitz syndrome gene MID1: similarities in subcellular localization and differences in expression during development.
The B-box family is an expanding new family of genes encoding proteins involved in diverse cellular functions such as developmental patterning and oncogenesis. A member of this protein family, MID1, is the gene responsible for the X-linked form of Opitz G/BBB syndrome, a developmental disorder characterized by defects of the midline structures. We now report the identification of MID2, a new transcript closely related to MID1. MID2 maps to Xq22 in human and to the syntenic region on the mouse X chromosome. The two X-linked genes share the same domains, the same exon-intron organization, a high degree of similarity at the protein level and the same subcellular localization, both being confined to the cytoplasm in association to micro-tubular structures. The expression pattern studied by RNA in situ hybridization in mouse revealed that Mid2 is expressed early in development and the highest level of expression is detected in the heart, unlike Mid1 for which no expression was detected in the developing heart. Together, these data suggest that midin and MID2 have a similar biochemical function but a different physiological role during development.
Telethon Institute of Genetics and Medicine (TIGEM), San Raffaele Biomedical Science Park, Via Olgettina 58, 20132 Milan, Italy.
G
G
Buchner
E
E
Montini
G
G
Andolfi
N
N
Quaderi
S
S
Cainarca
S
S
Messali
M T
MT
Bassi
A
A
Ballabio
G
G
Meroni
B
B
Franco
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002135:Calcium-Binding Proteins / Q000235:genetics*; D002874:Chromosome Mapping; D004247:DNA / Q000737:chemistry / Q000235:genetics; D018076:DNA, Complementary / Q000737:chemistry / Q000235:genetics; D004622:Embryo, Mammalian / Q000378:metabolism; D005314:Embryonic and Fetal Development; D005091:Exons; D019085:Fluorescent Antibody Technique, Direct; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D017403:In Situ Hybridization; D047908:Intracellular Signaling Peptides and Proteins; D007438:Introns; D008562:Membrane Glycoproteins; D008565:Membrane Proteins / Q000235:genetics*; D051379:Mice; D008810:Mice, Inbred C57BL; D008868:Microtubule Proteins; D008870:Microtubules / Q000378:metabolism; D008969:Molecular Sequence Data; D009115:Muridae; D009687:Nuclear Proteins; D012313:RNA / Q000235:genetics / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D019082:Smith-Lemli-Opitz Syndrome / Q000235:genetics*; D014018:Tissue Distribution; D014157:Transcription Factors / Q000235:genetics*; D044767:Ubiquitin-Protein Ligases; D014960:X Chromosome / Q000235:genetics
D002135:Calcium-Binding Proteins; D018076:DNA, Complementary; D047908:Intracellular Signaling Peptides and Proteins; C091625:MID2 protein, S cerevisiae; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D008868:Microtubule Proteins; D009687:Nuclear Proteins; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D012313:RNA; D004247:DNA; C109052:MID1 protein, human; D044767:Ubiquitin-Protein Ligases