Distinct but dispensable N-glycosylation of human CD69 proteins.
Human CD69 is uniquely glycosylated at typical (Asn-X-Ser/Thr) and atypical (Asn-X-Cys) motifs, which represents the molecular basis for the formation of CD69 homodimers and heterodimers. Here we examined the importance of N-glycosylation for the assembly and intracellular transport of CD69 proteins using mutant CD69 molecules that specifically lack typical and atypical N-glycan attachment motifs. These studies verify the importance of Cys residues in atypical triplet sequences for N-glycan addition to human CD69 proteins in the endoplasmic reticulum (ER). In addition, these data demonstrate that monoglycosylated CD69 proteins (bearing N-glycans exclusively at atypical or typical sites) and aglycosylated CD69 molecules (lacking N-glycans) efficiently dimerize in the ER and have similar stability as wild-type CD69 molecules. Finally, these results show that CD69 proteins lacking atypical or typical N-glycan addition sites are transported to the plasma membrane.
Vance
B A
BA
Department of Microbiology & Immunology, East Carolina University School of Medicine, Greenville, North Carolina, 27858-4354, USA.
Bennett
M J
MJ
Ward
Y
Y
Gress
R G
RG
Kearse
K P
KP
D000818:Animals; D015703:Antigens, CD / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019556:COS Cells; D019281:Dimerization; D006031:Glycosylation; D006801:Humans; D037181:Lectins, C-Type; D009154:Mutation; D011499:Protein Processing, Post-Translational; D000099192:CD69 Antigens
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D037181:Lectins, C-Type; D000099192:CD69 Antigens