Retina-specific expression of 5A11/Basigin-2, a member of the immunoglobulin gene superfamily.
OBJECTIVE
5A11/Basigin has recently been identified as a critical glycoprotein for full maturity and function of the mouse retina. However, the biological function of 5A11/Basigin has yet to be determined. Previous reports indicate the presence of multiple 5A11/Basigin polypeptides within the retina. Therefore, in an effort to determine the function of 5A11/Basigin, the molecular diversity of its expression was evaluated.


METHODS
Northern blot and immunoblot techniques were used to evaluate the number of forms of 5A11/Basigin in the mouse retina. cDNA cloning, using a mouse retina library or RT-PCR from rat, chicken, zebrafish, and human retina, was performed to determine the sequence of 5A11/Basigin transcripts. A peptide was generated, based on the deduced amino acid sequence, for subsequent antibody production. Localization of 5A11/Basigin expression was evaluated by immunoblot, immunohistochemistry, and real-time RT-PCR.


RESULTS
Two 5A11/Basigin transcripts of approximately 1.5 kb and approximately 1.8 kb, which correspond to glycosylated proteins of approximately 45 and approximately 55 kDa, respectively, were identified in mouse retina. The shorter form was previously cloned. However, the longer form, a splice variant of mouse 5A11/Basigin, is a member of the immunoglobulin gene superfamily and has been named 5A11/Basigin-2. Homologous transcripts were also cloned from rat, chicken, zebrafish, and human retina. 5A11/Basigin-2 expression was limited to the retina, specifically to photoreceptor cells, where it appeared to be most concentrated in the inner segments.


CONCLUSIONS
The specific and limited expression of 5A11/Basigin-2 explicitly within photoreceptor cells implies that this glycoprotein plays a fundamental role within the retina. However, its role remains to be determined.
Ochrietor
Judith D
JD
Whitney Laboratory of the University of Florida, St. Augustine, Florida 32080, USA. jdo@whitney.ufl.edu
Moroz
Tatiana P
TP
van Ekeris
Leslie
L
Clamp
Michael F
MF
Jefferson
Stephanie C
SC
deCarvalho
Ana C
AC
Fadool
James M
JM
Wistow
Graeme
G
Muramatsu
Takashi
T
Linser
Paul J
PJ
D000595:Amino Acid Sequence; D000818:Animals; D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; D001483:Base Sequence; D051926:Basigin; D001798:Blood Proteins; D015152:Blotting, Northern; D002645:Chickens; D003001:Cloning, Molecular; D020224:Expressed Sequence Tags; D019084:Fluorescent Antibody Technique, Indirect; D005803:Genes, Immunoglobulin; D014644:Genetic Variation; D006801:Humans; D015151:Immunoblotting; D007136:Immunoglobulins / Q000235:genetics; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000378:metabolism; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008969:Molecular Sequence Data; D020419:Photoreceptor Cells, Vertebrate / Q000378:metabolism*; D011817:Rabbits; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D015027:Zebrafish
D015703:Antigens, CD; D000951:Antigens, Neoplasm; D000954:Antigens, Surface; D030161:Avian Proteins; C497886:BSG protein, human; D001798:Blood Proteins; C102624:Bsg protein, Gallus gallus; C497887:Bsg protein, mouse; C079432:Bsg protein, rat; D007136:Immunoglobulins; D008562:Membrane Glycoproteins; C103658:synaptic glycoprotein gp65; D051926:Basigin