TCDB is operated by the Saier Lab Bioinformatics Group
Transporter Information:
Name: ATPase, Class II, type 9B
Symbol: ATP9B
TC: 3.A.3.8.3
Locations: 18q23
Aliases: ATPIIB
GenBank: R51412
Swiss-Prot: O43861
Accession Number: NM_198531
PubMed (9548971): Halleck MS, Pradhan D, Blackman C, Berkes C, Williamson P, Schlegel RA. Multiple members of a third subfamily of P-type ATPases identified by genomicsequences and ESTs.Genome Res. 1998 Apr;8(4):354-61. PMID: 9548971 [PubMed - indexed for MEDLINE]

The Saccharomyces cerevisiae genome contains five P-type ATPases divergent from both of the well-known subfamilies of these membrane ion transporters. This newly recognized third subfamily can be further divided into four classes of genes with nearly equal relatedness to each other. Genes of this new subfamily are also present and expressed in multicellular organisms such as Caenorhabditis elegans and mammals; some, but not all, can be assigned to the classes identified in yeast. Different classes of genes and different genes within a class are expressed differentially in tissues of the mouse. The recently cloned gene for the mammalian aminophospholipid translocase belongs to this new subfamily, suggesting that other subfamily members may transport other lipids or lipid-like molecules from one leaflet of the membrane bilayer to the other.

PubMed (11015572): Halleck MS, Lawler JF JR, Blackshaw S, Gao L, Nagarajan P, Hacker C, Pyle S,Newman JT, Nakanishi Y, Ando H, Weinstock D, Williamson P, Schlegel RA. Differential expression of putative transbilayer amphipath transporters.Physiol Genomics. 1999 Nov 11;1(3):139-50. PMID: 11015572 [PubMed - indexed for MEDLINE]

The aminophospholipid translocase transports phosphatidylserine and phosphatidylethanolamine from one side of a bilayer to another. Cloning of the gene encoding the enzyme identified a new subfamily of P-type ATPases, proposed to be amphipath transporters. As reported here, mammals express as many as 17 different genes from this subfamily. Phylogenetic analysis reveals the genes to be grouped into several distinct classes and subclasses. To gain information on the functions represented by these groups, Northern analysis and in situ hybridization were used to examine the pattern of expression of a panel of subfamily members in the mouse. The genes are differentially expressed in the respiratory, digestive, and urogenital systems, endocrine organs, the eye, teeth, and thymus. With one exception, all of the genes are highly expressed in the central nervous system (CNS); however, the pattern of expression within the CNS differs substantially from gene to gene. These results suggest that the genes are expressed in a tissue-specific manner, are not simply redundant, and may represent isoforms that transport a variety of different amphipaths.