Abstract
Human serotonin [5-hydroxytryptamine (5-HT)] transporters (hSERT, SHTT, and SLC6A4) inactivate S-HT after release and are prominent targets for therapeutic intervention in mood, anxiety, and obsessive-compulsive disorders. Multiple hSERT coding variants have been identified, although to date no comprehensive functional analysis of these variants has been reported. We transfected hSERT or 10 hSERT coding variants and examined total and surface protein expression, antagonist recognition, and transporter modulation by posttranslational, regulatory pathways. Two variants, Pro339Leu and Ile425Val, demonstrated significant changes in surface expression supporting alterations in 5-HT transport capacity (Vmax). Regardless of basal transport activity, all SERT variants displayed a capacity for rapid, phorbol ester-triggered down-regulation. Remarkably, five variants (Thr4Ala, Gly56Ala, Glu215Lys, Lys605Asn, and Pro612Ser) demonstrated no capacity for 5-HT uptake stimulation after acute protein kinase G (PKG)/p38 mitogen-activated protein kinase (MAPK) activation. Epstein-Barr virus (EBV)-transformed lymphocytes natively expressing the most common of these variants (Gly56Ala) exhibited a similar loss of 5-HT uptake stimulation by PKG p38 MAPK activators. HeLa cells transfected with the Gly56Ala variant demonstrated elevated basal phosphorylation and, unlike hSERT, could not be further phosphorylated after 8-bromo cGMP (8BrcGMP) treatments. These studies reveal cellular phenotypes associated with naturally occurring human SERT coding variants and suggest that altered transporter regulation by means of PKG/p38 MAPK-linked pathways may influence risk for disorders attributed to compromised 5-HT signaling.
| Original language | English |
|---|---|
| Pages (from-to) | 11545-11550 |
| Number of pages | 6 |
| Journal | Proceedings of the National Academy of Sciences of the United States of America |
| Volume | 102 |
| Issue number | 32 |
| DOIs | |
| State | Published - Aug 9 2005 |
| Externally published | Yes |
Fingerprint
Keywords
- Antidepressant
- Autism
- Polymorphism
- Regulation
- Transport
ASJC Scopus subject areas
- Genetics
- General
Cite this
Human serotonin transporter variants display altered sensitivity to protein kinase G and p38 mitogen-activated protein kinase. / Prasad, Harish C.; Zhu, Chong Bin; McCauley, Jacob L; Samuvel, Devadoss J.; Ramamoorthy, Sammanda; Shelton, Richard C.; Hewlett, William A.; Sutcliffe, James S.; Blakely, Randy D.
In: Proceedings of the National Academy of Sciences of the United States of America, Vol. 102, No. 32, 09.08.2005, p. 11545-11550.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Human serotonin transporter variants display altered sensitivity to protein kinase G and p38 mitogen-activated protein kinase
AU - Prasad, Harish C.
AU - Zhu, Chong Bin
AU - McCauley, Jacob L
AU - Samuvel, Devadoss J.
AU - Ramamoorthy, Sammanda
AU - Shelton, Richard C.
AU - Hewlett, William A.
AU - Sutcliffe, James S.
AU - Blakely, Randy D.
PY - 2005/8/9
Y1 - 2005/8/9
N2 - Human serotonin [5-hydroxytryptamine (5-HT)] transporters (hSERT, SHTT, and SLC6A4) inactivate S-HT after release and are prominent targets for therapeutic intervention in mood, anxiety, and obsessive-compulsive disorders. Multiple hSERT coding variants have been identified, although to date no comprehensive functional analysis of these variants has been reported. We transfected hSERT or 10 hSERT coding variants and examined total and surface protein expression, antagonist recognition, and transporter modulation by posttranslational, regulatory pathways. Two variants, Pro339Leu and Ile425Val, demonstrated significant changes in surface expression supporting alterations in 5-HT transport capacity (Vmax). Regardless of basal transport activity, all SERT variants displayed a capacity for rapid, phorbol ester-triggered down-regulation. Remarkably, five variants (Thr4Ala, Gly56Ala, Glu215Lys, Lys605Asn, and Pro612Ser) demonstrated no capacity for 5-HT uptake stimulation after acute protein kinase G (PKG)/p38 mitogen-activated protein kinase (MAPK) activation. Epstein-Barr virus (EBV)-transformed lymphocytes natively expressing the most common of these variants (Gly56Ala) exhibited a similar loss of 5-HT uptake stimulation by PKG p38 MAPK activators. HeLa cells transfected with the Gly56Ala variant demonstrated elevated basal phosphorylation and, unlike hSERT, could not be further phosphorylated after 8-bromo cGMP (8BrcGMP) treatments. These studies reveal cellular phenotypes associated with naturally occurring human SERT coding variants and suggest that altered transporter regulation by means of PKG/p38 MAPK-linked pathways may influence risk for disorders attributed to compromised 5-HT signaling.
AB - Human serotonin [5-hydroxytryptamine (5-HT)] transporters (hSERT, SHTT, and SLC6A4) inactivate S-HT after release and are prominent targets for therapeutic intervention in mood, anxiety, and obsessive-compulsive disorders. Multiple hSERT coding variants have been identified, although to date no comprehensive functional analysis of these variants has been reported. We transfected hSERT or 10 hSERT coding variants and examined total and surface protein expression, antagonist recognition, and transporter modulation by posttranslational, regulatory pathways. Two variants, Pro339Leu and Ile425Val, demonstrated significant changes in surface expression supporting alterations in 5-HT transport capacity (Vmax). Regardless of basal transport activity, all SERT variants displayed a capacity for rapid, phorbol ester-triggered down-regulation. Remarkably, five variants (Thr4Ala, Gly56Ala, Glu215Lys, Lys605Asn, and Pro612Ser) demonstrated no capacity for 5-HT uptake stimulation after acute protein kinase G (PKG)/p38 mitogen-activated protein kinase (MAPK) activation. Epstein-Barr virus (EBV)-transformed lymphocytes natively expressing the most common of these variants (Gly56Ala) exhibited a similar loss of 5-HT uptake stimulation by PKG p38 MAPK activators. HeLa cells transfected with the Gly56Ala variant demonstrated elevated basal phosphorylation and, unlike hSERT, could not be further phosphorylated after 8-bromo cGMP (8BrcGMP) treatments. These studies reveal cellular phenotypes associated with naturally occurring human SERT coding variants and suggest that altered transporter regulation by means of PKG/p38 MAPK-linked pathways may influence risk for disorders attributed to compromised 5-HT signaling.
KW - Antidepressant
KW - Autism
KW - Polymorphism
KW - Regulation
KW - Transport
UR - http://www.scopus.com/inward/record.url?scp=23844454012&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=23844454012&partnerID=8YFLogxK
U2 - 10.1073/pnas.0501432102
DO - 10.1073/pnas.0501432102
M3 - Article
C2 - 16055563
AN - SCOPUS:23844454012
VL - 102
SP - 11545
EP - 11550
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
SN - 0027-8424
IS - 32
ER -