Cimmaruta, Chiara
(2018)
ANALYSIS OF A RARE GENETIC DISEASE DUE TO PROTEIN INSTABILITY: STUDY AND CHARACTERIZATION OF CONGENITAL DISORDER OF GLYCOSYLATION TYPE IA.
[Tesi di dottorato]
Item Type: |
Tesi di dottorato
|
Lingua: |
Italiano |
Title: |
ANALYSIS OF A RARE GENETIC DISEASE DUE TO PROTEIN INSTABILITY: STUDY AND CHARACTERIZATION OF CONGENITAL DISORDER OF GLYCOSYLATION TYPE IA |
Creators: |
Creators | Email |
---|
Cimmaruta, Chiara | chiara.cimmaruta@unina.it |
|
Date: |
December 2018 |
Number of Pages: |
66 |
Institution: |
Università degli Studi di Napoli Federico II |
Department: |
Biologia |
Dottorato: |
Biologia |
Ciclo di dottorato: |
31 |
Coordinatore del Corso di dottorato: |
nome | email |
---|
Cozzolino, Salvatore | salvatore.cozzolino@unina.it |
|
Tutor: |
nome | email |
---|
Cubellis, Maria Vittoria | UNSPECIFIED |
|
Date: |
December 2018 |
Number of Pages: |
66 |
Uncontrolled Keywords: |
CDG-IA; fosfomannomutasi2 |
Settori scientifico-disciplinari del MIUR: |
Area 05 - Scienze biologiche > BIO/10 - Biochimica |
[error in script]
[error in script]
Date Deposited: |
03 Jan 2019 14:20 |
Last Modified: |
30 Jun 2020 08:51 |
URI: |
http://www.fedoa.unina.it/id/eprint/12499 |

Abstract
Congenital disorder of glycosylation type Ia (CDG-Ia ) is an autosomal recessive disease caused by mutations in PMM2 gene encoding phosphomannomutase 2. In humans two PMM enzymes exist, PMM1 and PMM2; both of them catalyze the interconversion of mannose-6-phosphate into mannose-1-phosphate but only PMM1 can also hydrolyze bis-phosphate hexoses after stimulation with inosine monophosphate (IMP). Although no mutation in PMM1 gene has been associated with the disease, the role of the paralogous enzyme in CDG-Ia should be clarified. PMM1 and PMM2 were analyzed by conventional enzymatic assays as well as by novel techniques such as 31P-NMR and thermal shift assay. In order to evaluate the role of IMP in regulating mannose-1-phosphate production and ultimately protein glycosylation, it was performed the characterization of a triple mutant of PMM1 that retains mutase and phosphatase activity, but not sensitive to IMP.
For the purpose of developing a therapeutic approach for CDG-Ia, for which there is no cure at the moment, it was generated a new cell model in order to identify biomarkers for cell-based screening, such as glycosylated proteins. A cancer cell line HepG2 was edited by Crispr/Cas9 system to introduce the hypomorphic PMM2 mutation, F119L, that has been observed in CDG-Ia patients in homozygosity. Hypo-glycosylated forms of α-1-anti-trypsin (AAT) was detected by Western blot in HepG2-F119L similarly to the serum from CDG-Ia patients. Furthermore, a difference in the amount of a secreted protein, alpha-fetoprotein (AFP), which is N-glycosylated, was found in HepG2-F119L secretome compared to the control cells. These results suggest that HepG2-F119L represent a good cell model for CDG-Ia and a useful tool for drug screening since they are defective in N-glycosylation of serum proteins that are found altered in patients. Further studies will be performed to propose AFP as a suitable biomarker.
Downloads per month over past year
Actions (login required)
 |
View Item |