DSCR2, a Down syndrome critical region protein, is localized to the endoplasmic reticulum of mammalian cells.
We used immunocytochemical and fluorescence assays to investigate the subcellular location of the protein encoded by Down syndrome critical region gene 2 (DSCR2) in transfected cells. It was previously suggested that DSCR2 is located in the plasma membrane as an integral membrane protein. Interestingly, we observed this protein in the endoplasmic reticulum (ER) of cells. We also studied whether the truncated forms of DSCR2 showed different subcellular distributions. Our observations indicate that DSCR2 probably is not inserted into the membrane of the endoplasmic reticulum since the fragments lacking the predicted transmembrane (TM) helices remained associated with the ER. Our analyses suggest that, although DSCR2 is associated with the endoplasmic reticulum, it is not an integral membrane protein and it is maintained on the cytoplasmic side of the ER by indirect interaction with the ER membrane or with another protein.
Possik
P A
PA
Department of Genetics and Evolution, Federal University of São Carlos, São Carlos, SP, Brazil.
Sommer
C A
CA
Issa Hori
J
J
Machado-Santelli
G M
GM
Jamur
M C
MC
Henrique-Silva
F
F
D000818:Animals; D016466:CHO Cells; D019556:COS Cells; D002460:Cell Line; D002522:Chlorocebus aethiops; D006224:Cricetinae; D004314:Down Syndrome / Q000235:genetics*; D004721:Endoplasmic Reticulum / Q000378:metabolism* / Q000648:ultrastructure; D018507:Gene Expression Regulation, Developmental; D049452:Green Fluorescent Proteins / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D018832:Molecular Chaperones; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism* / Q000648:ultrastructure; D016297:Mutagenesis, Site-Directed; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D017384:Sequence Deletion
D008565:Membrane Proteins; D018832:Molecular Chaperones; D009124:Muscle Proteins; C410584:PSMG1 protein, human; D011993:Recombinant Fusion Proteins; C485184:enhanced green fluorescent protein; D049452:Green Fluorescent Proteins