Inhibiting farnesylation of progerin prevents the characteristic nuclear blebbing of Hutchinson-Gilford progeria syndrome.
Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder that is characterized by dramatic premature aging and accelerated cardiovascular disease. HGPS is almost always caused by a de novo point mutation in the lamin A gene (LMNA) that activates a cryptic splice donor site, producing a truncated mutant protein termed "progerin." WT prelamin A is anchored to the nuclear envelope by a farnesyl isoprenoid lipid. Cleavage of the terminal 15 aa and the farnesyl group releases mature lamin A from this tether. In contrast, this cleavage site is deleted in progerin. We hypothesized that retention of the farnesyl group causes progerin to become permanently anchored in the nuclear membrane, disrupting proper nuclear scaffolding and causing the characteristic nuclear blebbing seen in HGPS cells. Also, we hypothesized that blocking farnesylation would decrease progerin toxicity. To test this hypothesis, the terminal CSIM sequence in progerin was mutated to SSIM, a sequence that cannot be farnesylated. SSIM progerin relocalized from the nuclear periphery into nucleoplasmic aggregates and produced no nuclear blebbing. Also, blocking farnesylation of authentic progerin in transiently transfected HeLa, HEK 293, and NIH 3T3 cells with farnesyltransferase inhibitors (FTIs) restored normal nuclear architecture. Last, treatment of both early- and late-passage human HGPS fibroblasts with FTIs resulted in significant reductions in nuclear blebbing. Our results suggest that treatment with FTIs represents a potential therapy for patients with HGPS.
Capell
Brian C
BC
Genome Technology Branch, National Human Genome Research Institute, National Institutes of Health, 50 South Drive, MSC 8004, Bethesda, MD 20892-8004, USA.
Erdos
Michael R
MR
Madigan
James P
JP
Fiordalisi
James J
JJ
Varga
Renee
R
Conneely
Karen N
KN
Gordon
Leslie B
LB
Der
Channing J
CJ
Cox
Adrienne D
AD
Collins
Francis S
FS
D019883:Alkyl and Aryl Transferases / Q000037:antagonists & inhibitors / Q000378:metabolism; D000818:Animals; D002460:Cell Line; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism* / Q000473:pathology*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D051231:Farnesyltranstransferase; D006801:Humans; D034904:Lamin Type A / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism*; D051379:Mice; D009154:Mutation / Q000235:genetics; D011371:Progeria / Q000188:drug therapy / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D017368:Protein Prenylation / Q000187:drug effects
D004791:Enzyme Inhibitors; D034904:Lamin Type A; D019883:Alkyl and Aryl Transferases; D051231:Farnesyltranstransferase