Expression of betaB(2)-crystallin mRNA and protein in retina, brain, and testis.
OBJECTIVE
To evaluate the expression of betaB(2)-crystallin mRNA and protein in rat, bovine, and human nonlens and nonocular tissues.


METHODS
betaB(2)-crystallin mRNA levels were detected by RT-PCR. betaB(2)-crystallin protein was purified from rat and bovine tissues by FPLC chromatography. FPLC fractions were analyzed by immunoblotting. The identity of betaB(2)-crystallin protein, isolated from the retina, was confirmed by protein microsequencing.


RESULTS
betaB(2)-crystallin transcript was detected in rat brain, rat testis, and human retina by RT-PCR. betaB(2)-crystallin transcript was not found in rat lung, heart, ovary, spleen, thymus, kidney, and liver or in human brain and testis. betaB(2)-crystallin protein was partially purified from and its identity confirmed in rat brain, rat testis, and bovine retina. The bovine retinal protein was further confirmed to be authentic betaB(2)-crystallin by protein microsequencing.


CONCLUSIONS
These results establish that betaB(2)-crystallin mRNA and protein are expressed in tissues outside of the lens and outside of the eye including retina, brain, and testis. Extralenticular and extraocular expression of betaB(2)-crystallin, coupled with its participation in phosphorylation pathways, suggests that it has nonrefractive functions in these tissues.
Magabo
K S
KS
Department of Biology, West Virginia University, Morgantown 26505, USA.
Horwitz
J
J
Piatigorsky
J
J
Kantorow
M
M
D000818:Animals; D001921:Brain / Q000378:metabolism*; D002417:Cattle; D002851:Chromatography, High Pressure Liquid; D003459:Crystallins / Q000096:biosynthesis / Q000235:genetics*; D017931:DNA Primers / Q000737:chemistry; D015870:Gene Expression; D006801:Humans; D015151:Immunoblotting; D008297:Male; D012333:RNA, Messenger / Q000096:biosynthesis*; D051381:Rats; D012160:Retina / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013737:Testis / Q000378:metabolism*; D038206:beta-Crystallin B Chain / Q000031:analogs & derivatives*
D003459:Crystallins; D017931:DNA Primers; D012333:RNA, Messenger; D038206:beta-Crystallin B Chain; C113634:beta-crystallin B2