ENGINEERING NEW METABOLIC PATHWAYS IN ISOLATED CELLS FOR THE DEGRADATION OF GUANIDINOACETIC ACID AND SIMULTANEOUS PRODUCTION OF CREATINE

1 . An isolated cell modified for catalyzing the conversion of guanidinoacetate acid (GAA) into creatine in the presence of glucose and methionine using an exogenous guanidinoacetate methyltransferase (GAMT) and methionine adenosyltransferase (MAT) protein.

2 . The isolated cell according to claim 1 , wherein the cell is a human cell.

3 . The isolated cell according to claim 1 , wherein the cell is selected from erythrocyte, hepatocyte, pancreas cell.

4 . The isolated cell according to claim 1 , wherein said cell lacks or exhibits a reduced endogenous GAMT and/or MAT enzymatic activity.

5 . The isolated cell according to claim 1 , wherein said cell is isolated from a subject suffering of Guanidinoacetate methyltransferase (GAMT) deficiency.

6 . The isolated cell according to claim 1 , wherein said cell is loaded with said GAMT protein, a fragment or a variant thereof, and with said MAT protein, a fragment or a variant thereof.

7 . The isolated cell according to claim 1 , wherein said cell is transformed or transfected with exogenous nucleic acids comprising at least a nucleic acid sequence encoding said GAMT protein, a fragment or a variant thereof, and a nucleic acid sequence encoding at least said MAT protein, a fragment or a variant thereof, wherein said a fragment or a variant thereof having the same or improved enzymatic activity of the wild-type protein.

8 . The isolated cell according to claim 1 , wherein said GAMT and MAT are the naturally or recombinant human GAMT and MAT.

9 . The isolated cell according to claim 1 , wherein said GAMT is the wild-type GAMT having the sequence SEQ ID NO 1 wherein one or more of the following mutations are inserted in the sequence of said protein: A26N, L37M, I187Q and V215Q.

10 . The isolated cell according to claim 1 , wherein said GAMT is the GAMT having the SEQ ID NO 1, SEQ ID NO 2, SEQ ID NO 3, SEQ ID NO 4 or SEQ ID NO 32 and said MAT is the MAT2A having the SEQ ID NO 5, or their variants with at least 98% identity.

11 . The isolated cell according to claim 1 , wherein said GAMT protein, a fragment or variant thereof, and said MAT protein, a fragment or variant thereof, are present in said cell in a ratio ranging from 10:1 to 1:10.

12 . (canceled)

13 . A method of treating a subject suffering from a disease or condition caused by and/or characterized by a deficit of creatine, comprising administering the isolated cell of claim 1 to the subject.

14 . The method of claim 13 , wherein the disease or condition is GAMT deficiency, creatine transporter deficiency, methionine-dependent tumors.

15 . A pharmaceutical composition comprising a plurality of modified cells according to claim 1 and one or more carriers and/or diluent.

16 . An in vitro method for the preparation of a modified cell comprising a step of modifying a cell whereby said cell is capable of catalyzing the conversion of guanidinoacetate acid (GAA) into creatine in the presence of glucose and methionine using an exogenous guanidinoacetate methyltransferase (GAMT) and methionine adenosyltransferase (MAT) protein.

17 . The isolated cell according to claim 6 , wherein said MAT is the catalytic subunit MAT2A, wherein said a fragment or a variant thereof having the same or improved enzymatic activity of the wild-type protein.

18 . The isolated cell according to claim 8 , wherein said MAT is the catalytic subunit MAT2A.

19 . The isolated cell according to claim 9 , wherein all of said mutations are inserted.

20 . A method of treating GAMT deficiency, creatine transporter deficiency, methionine dependent tumors in a subject, comprising administering the pharmaceutical composition of claim 15 to said subject.