CD240D RhD (Rhesus blood group D antigen), RH1, Rh30D
Molecule TypeAntigen ExpressionMolecular Weight
Min / Max
Lineage Restricted Molecule
Type 3 glycoprotein, 12 span
Erythrocyte
Red Cell
30 / 30

Expression
CD240D is expressed on the surface of red blood cells, restricted to tissues or cell lines of erythrocytes and erythroid progenitors.

Structure
MOLECULAR FAMILY NAME: Belongs to the rhesus blood group family.

CD240D is a multi-pass type-3, 12 span 417 aa glycoprotein.  It contains an extracellular domain,  12 transmembrane helical domains and 5 cysteine residues, 2 of which are intracellular and palmitoylated and a cytoplasmic domain which has a N- and C-terminal located inside the cell. 

MOLECULAR MASS
Cell Type Unreduced Reduced
30-32 kDa

POST-TRANSCRIPTIONAL MODIFICATION

Alternative splicing yields 3 transcript variants encoding 3 different isoforms.


POST-TRANSLATIONAL MODIFICATION

CD240D is non-glycosylated. protein.

Ligands
LIGANDS AND MOLECULES ASSOCIATED WITH CD240D: No information.

Function
CD240D belongs to the Rh blood group system.  CD240D is closely associated in the erythrocyte membrane with the Rh-associated glycoprotein CD241 (RhAG), CD242 (ICAM-4, LW), CD47 and CD235b (glycophorin B).  The core of the Rh complex is thought to consist of two Rh subunits and two CD241 subunits, to which CD47, CD235b and and CD242 associate noncovalently.  This system is one of the polymorphic in the blood group and is comprised of 45 antigens.  The Rh antigen may promote the export of ammonium.  The classification of Rh-positive and Rh-negative individuals is determined by the presence or absence of the highly immunogenic CD240D protein on the surface of erythrocytes.   The function of this large complex is unclear but there is evidence to suggest CD240D assists in maintaining the mechanical properties of the erythrocyte by association with ankyrin-R of the red cell skeleton.

The Rh blood group system is the second most clinically significant of the blood groups, second only to ABO.  It is also the most polymorphic of the blood groups, with variations due to deletions, gene conversions, and missense mutations.  The Rh blood group includes the CD240D gene, which encodes the protein, and a second gene that encodes both the RhC and RhE antigens on a single polypeptide.  CD240D is the most immunogenic and clinically important of the Rh system.  In 12-18% of Caucasians, the D-negative phenotype is almost always the result of homozygosity for a deletion of the entire RHD gene.  In 5% of Africians, the D-negative phenotype can be due to the deletion of RHD, the presence of a RHD pseudogene RHDpsi or the presence of a hybrid gene CD240DCE.  In 100% of people from the Far East are D-positive.

BIOCHEMICAL ACTIVITY: No information.

DISEASE RELEVANCE AND FUNCTION OF CD240D IN INTACT ANIMAL

The RhD phenotype of an individual has implications in alloimmune transfusion reactions and hemolytic disease of the newborn.


Comments
MOLECULAR INTERACTIONS -
PROTEINS AND DNA ELEMENTS WHICH REGULATE TRANSCRIPTION OF CD240D: No information.

SUBSTRATES: No information.

ENZYMES WHICH MODIFY CD240D: No information.


Database accession numbers
AnimalPIRSWISSPROTEMGBL/GENBANK
 
HumanEntrezgene 6007Q02161
Antibodies

Revised June 25, 2008


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