Multiple phosphorylated isoforms of NRL are expressed in rod photoreceptors.
NRL, a bZIP transcription factor of the Maf subfamily, interacts with the homeodomain protein CRX and synergistically regulates rhodopsin expression. Here we report that six isoforms of NRL (29-35 kDa) are generated by phosphorylation and expressed specifically in the mammalian retina. The anti-NRL antibody also cross-reacts with a cytosolic 45-kDa protein, which is detected in neuronal tissues but is not encoded by the NRL gene. In both human retinal cell cultures and sections of fetal and adult human retina, NRL is present in the nuclei of developing and mature rods but not cones. We propose that NRL regulates rod photoreceptor-specific gene expression and is involved in rod differentiation.
Swain
P K
PK
Department of Ophthalmology, University of Michigan, Ann Arbor, Michigan 48105, USA.
Hicks
D
D
Mears
A J
AJ
Apel
I J
IJ
Smith
J E
JE
John
S K
SK
Hendrickson
A
A
Milam
A H
AH
Swaroop
A
A
D000469:Alkaline Phosphatase / Q000494:pharmacology; D000818:Animals; D050976:Basic-Leucine Zipper Transcription Factors; D019556:COS Cells; D002454:Cell Differentiation; D002467:Cell Nucleus / Q000378:metabolism; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D004591:Electrophoresis, Polyacrylamide Gel; D005136:Eye Proteins / Q000096:biosynthesis* / Q000737:chemistry*; D006801:Humans; D015151:Immunoblotting; D007150:Immunohistochemistry; D051379:Mice; D018345:Mice, Knockout; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism; D010766:Phosphorylation; D020033:Protein Isoforms; D011994:Recombinant Proteins / Q000378:metabolism; D012160:Retina / Q000196:embryology / Q000378:metabolism; D017948:Retinal Rod Photoreceptor Cells / Q000378:metabolism*; D012243:Rhodopsin / Q000096:biosynthesis; D013997:Time Factors; D014162:Transfection
D050976:Basic-Leucine Zipper Transcription Factors; D004268:DNA-Binding Proteins; D005136:Eye Proteins; C490037:NRL protein, human; C084884:Nrl protein, mouse; D020033:Protein Isoforms; D011994:Recombinant Proteins; D012243:Rhodopsin; D000469:Alkaline Phosphatase; D010744:Phosphoric Monoester Hydrolases