PLAC1
Description
The PLAC1 (placenta enriched 1) is a protein-coding gene located on chromosome X.
Placenta-specific protein 1 is a small (212 amino acid), secreted cell surface protein encoded on the X-chromosome by the PLAC1 gene. Since its discovery in 1999, PLAC1 has been found to play a role in placental development and maintenance, several gestational disorders including preeclampsia , fetal development and a large number of cancers.
== Genomics == PLAC1 is located on the long arm of the X-chromosome at Xq26.3. The gene consists of six Exons spanning nearly 200Kb (GRCh38/hgs38; X:134,565,838 - 134,764,322). The entire coding sequence plus the 3’ UTR and part of the 5’ UTR constitute Exon 6 while Exons 1 – 5 contain variously spliced elements of the rest of the 5’UTR including two independently regulated promoters. These two promoters, termed P1 (or distal) and P2 (or proximal) are located in Exons 1 and 4 respectively. They have been shown to produce transcripts simultaneously though P1 transcription predominates in cancers and P2 transcription predominates in placentae.
== Phylogenetics == From its initial description, the consensus is that PLAC1 is highly conserved and that this conservation reflects an important role in the establishment and maintenance of the placenta. A detailed study of the PLAC1 gene and protein among 54 placental mammal species representing twelve crown orders confirms a high level of conservation under the control of strict purifying selection. Further, comparative genomic sequences from two marsupials, the opossum (Mondelphis domestica) and the wallaby (Macropus eugenii), a monotreme, the platypus (Ornithorhynchus anatinus), two avians, the chicken (Gallus gallus) and the finch (Taeniopygia guttata), and two fish, the zebrafish (Danio rerio) and the stickleback (Gasterosteus arculeatus) spanning the synthenic X-chromosome region from PHD finger protein 6 (PHD6) through Factor 9 (F9) were screened for any sequences similar to PLAC1.
PLAC1 is also known as CT92, OOSP2B, OOSP2L.
