Molecular characterization of the murine orthologue of the human retinal proteoglycan IPM 150.
OBJECTIVE
We recently identified a family of novel human proteoglycans/glycoproteins that are major constituents of the human interphotoreceptor matrix. Two members of this family, designated IPM 150 and IPM 200, have been extensively characterized. Although the IPM is thought to mediate crucial roles in retinal physiology, including retinal adhesion and photoreceptor cell viability, little is known about the roles of specific IPM constituents in these processes. In order to characterize the mouse IPM 150 orthologue, to initiate functional in vivo studies, and as a prerequisite towards future genetic manipulation, we cloned the murine orthologue of human IPM 150 and determined its chromosomal location.


METHODS
A mouse retinal cDNA library was screened using an IMAGE clone with sequence similarity to human IPM 150. The genomic location of the mouse IPM 150 gene was determined by radiation hybrid analyses.


RESULTS
We describe here the molecular structure of the murine orthologue of human IPM 150 and place the location of its gene on mouse chromosome 9. Among the tissues examined, expression of IPM 150 appeared to be restricted to the retina.


CONCLUSIONS
Comparison of the human and murine IPM 150 core proteins revealed that the molecules are generally well conserved, although several potentially significant differences do exist. In addition, two highly conserved domains within the core proteins were identified. The data presented here represent a first step towards the development of experimental murine models, which may eventually be used to elucidate the mechanisms underlying retinal adhesion and photoreceptor survival.
Kuehn
M H
MH
Center for Macular Degeneration, Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA 52240, USA.
Wietecki
D T
DT
Hageman
G S
GS
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002874:Chromosome Mapping; D017124:Conserved Sequence; D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D011509:Proteoglycans / Q000235:genetics* / Q000378:metabolism; D012160:Retina / Q000378:metabolism*
D016326:Extracellular Matrix Proteins; D005136:Eye Proteins; C486428:IMPG1 protein, human; C486429:IMPG1 protein, mouse; D011509:Proteoglycans