Genomic organization of a novel glycosylphosphatidylinositol MAM gene expressed in human tissues and tumors.
We report the genomic organization of a novel human gene mapped to chromosome 6p21, encoding a putative glycosylphosphatidylinositol (GPI) anchored protein containing a MAM (meprin, A5 antigen, protein tyrosine phosphatase mu) domain, that we have termed as GPIM (GPI and MAM) protein. GPIM gene consists of an 8.9 kb transcript composed of 17 coding exons spanning about 65.5 kb of genomic DNA. The deduced polypeptide consists of 955 amino acids and exhibits structural features found in different types of cell adhesion molecules (CAMs), such as the presence of immunoglobulin domains, the presence of a MAM domain or the capacity to anchor to the cell membrane by a GPI motif. Expression analysis in normal human tissues revealed that this gene is expressed as a 5 kb and 9.5 kb mRNA. Furthermore, the smaller transcript is highly expressed in some human cancer cell lines, as well as in different primary tumors (lung, colon, uterus, stomach and breast). Interestingly, the gene was higher expressed in several tumor tissues analysed as compared to their corresponding normal tissues. Thus, GPIM is a novel gene codifying a protein with structural features characteristics of some CAMs, which might be involved in the tumor progression.
De Juan
Carmen
C
Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad Complutense de Madrid, 28040 Madrid, Spain.
Iniesta
Pilar
P
González-Quevedo
Rosa
R
Morán
Alberto
A
Sánchez-Pernaute
Andrés
A
Torres
Antonio J
AJ
Balibrea
Jose Luis
JL
Díaz-Rubio
Eduardo
E
Cruces
Jesús
J
Benito
Manuel
M
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002417:Cattle; D015815:Cell Adhesion Molecules / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D002896:Chromosomes, Human, Pair 6 / Q000235:genetics*; D004273:DNA, Neoplasm / Q000235:genetics; D018450:Disease Progression; D020224:Expressed Sequence Tags; D005260:Female; D058851:GPI-Linked Proteins; D015870:Gene Expression; D005796:Genes; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D006801:Humans; D008297:Male; D051379:Mice; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000235:genetics*; D009369:Neoplasms / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D019006:Neural Cell Adhesion Molecules; D009928:Organ Specificity; D017434:Protein Structure, Tertiary; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured / Q000378:metabolism
D015815:Cell Adhesion Molecules; D004273:DNA, Neoplasm; D058851:GPI-Linked Proteins; D017261:Glycosylphosphatidylinositols; C460759:MDGA1 protein, human; D009363:Neoplasm Proteins; D019006:Neural Cell Adhesion Molecules; D012333:RNA, Messenger