title: Calreticulin is a binding protein for muramyl dipeptide and peptidoglycan in RK13 cells.
abstract: Calreticulin (CRT) was isolated and identified as a protein in rabbit kidney RK(13) cells that binds the apoptogenic bacterial cell wall (BCW) components, muramyl dipeptide (MDP) and peptidoglycan (PG). Mannan-agarose purified RK(13) cell CRT (rCRT) selectively bound sepharose-immobilized L,D-MDP and PG, but not L,L-MDP or D,D-MDP. Purified rCRT and bovine CRT (bCRT) also bound free PG and L,D-MDP demonstrated in bioassays of RK(13) cell apoptosis. The results suggest that, in RK(13) cells, (a) CRT is a specific binding protein for both L,D-MDP and PG and (b) CRT binding L,D-MDP or PG is dependent on the stereoisomeric configuration of the dipeptide (L-alanyl-D-isoglutamine) moiety. In addition, the results also suggest that, in RK(13) cells, the binding of L,D-MDP, L,L-MDP, D,D-MDP, or PG to CRT correlates with their capacities of inducing apoptosis.
authors.affiliation: Department of Ophthalmology, Louisiana State University Health Sciences Center, Shreveport, Louisiana 71130-3932, USA. dchen@lsuhsc.edu
authors.forename: Dequan
authors.initials: D
authors.lastname: Chen
authors.forename: Chris
authors.initials: C
authors.lastname: Duggan
authors.forename: Tomas B
authors.initials: TB
authors.lastname: Reden
authors.forename: Lakshmana M
authors.initials: LM
authors.lastname: Kooragayala
authors.forename: Donald E
authors.initials: DE
authors.lastname: Texada
authors.forename: Marlyn P
authors.initials: MP
authors.lastname: Langford
mesh_terms: D000119:Acetylmuramyl-Alanyl-Isoglutamine / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001426:Bacterial Proteins / Q000737:chemistry / Q000378:metabolism; D037282:Calreticulin / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002460:Cell Line; D007668:Kidney / Q000166:cytology; D010457:Peptidoglycan / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D011817:Rabbits
chemical_list: D001426:Bacterial Proteins; D037282:Calreticulin; D010457:Peptidoglycan; D000119:Acetylmuramyl-Alanyl-Isoglutamine