Glycodelin A:

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Glycodelin A An immunocalin with apoptotic
activity
Anjali A Karande Debaditya Mukhopadhyay Rajesh
Jayachandran Swathi SundarRaj Department of
Biochemistry, Indian Institute of Science,
Bangalore 560 012, India
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Glycodelin

• A 162 amino acid secreted protein present in
• both female (GdA) and male (GdS) reproductive
• tissues.
• Gd is a member of the lipocalin superfamily.
• 54.6 identical to b lactoglobulin.
• The two major isoforms differ only in their
• complex glycosylation which dictates the
• function of these proteins..

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IsoformsIdentical aminoacid sequence,
differential glycosylation
Glycodelin S (GdS) Male reproductive
tract. Absence of sialic acid. Unusually fucose
rich. N-28 5-7 mannose. N-63 1-5 fucose, Lewis
Y (defucosylated tetrasaccharide). pI 5.2-5.4.
Glycodelin A (GdA) Female reproductive
tract. Rich in sialic acid (N-acetyl neuraminic
acid). Not fucose rich. N-28 galactose, fucose,
4-5 mannose, sialic acid. N-63 1-2 fucose,
sialic acid, Lewis X and Lewis Y structures. pI
4.8-4.9.
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GdA induces apoptosis in PBMCs
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GLYCODELIN A EXHIBITS APOPTOTIC ACTIVITY
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Glycodelin A induces apoptosis in activated T
cells Does glycodelin exhibit the same activity?
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Adapted from Dell A, et al, J. Biol. Chem.
(1995), 270, 24116-24126 and Morris HR et al,
J. Biol Chem. (1996) 271, 32159-32167
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Does deglycosylated glycodelin show apoptotic
activity?
PNGase/EndoH do not deglycosylate glycodelin A
under non-denaturing conditions
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Desialylated GdA loses its immunosuppressive
activity
GdA
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ROLE OF GLYCOSYLATION ? Glycodelin gene was
cloned and expressed in Baculovirus system and
found to be active Glycosylation sites N28
N63 were mutated to Q BOTH SINGLE MUTANT
Gly-BAC PROTEINS, N28Q N63Q AND THE DOUBLE
MUTANT PROTEIN, N28QN63Q RETAINED THEIR APOPTOTIC
ACTIVITY
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Mechanism of apoptosis induction by glycodelin
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Is glycodelin induced apoptosis caspase
dependant?
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Jurkat cells cultured for 12 h with glycodelinA
Apoptotic population determined
ZVAD-FMK cell permeable broad spectrum caspase
inhibitor
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Is glycodelin induced apoptosis mediated by CD95
(Fas)
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GdA does not act through Fas to induce apoptosis
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Caspase 8 does not initiate apoptosis in GdA
induced death
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Does JNK get activated in GdA induced Apoptosis
?
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JNK does not play a part in GdA indced apoptosis
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Role of Caspase 9 in GdA induced apoptosis
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Caspase 9 inhibitor partially rescues GdA
induced death
Mitochondria gets damaged in GdA induced
apoptosis
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Mitochondrial potential loss and JC1 assay
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Mitochondrial potential loss precedes apoptotic
DNA loss
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Glycodelin induced cell death signaling a)
does not involve CD95 (Fas) b) does not involve
caspase 8 and hence not any known death
receptors c) JNK signaling path way is not
activated. d) apoptotic signaling is most
probably initiated at the mitochondria like
other stress induced apoptosis.