Ownership Submission
FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
SCHMERTZLER MICHAEL
  2. Issuer Name and Ticker or Trading Symbol
PTC THERAPEUTICS, INC. [PTCT]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
1300 VALLEY ROAD
3. Date of Earliest Transaction (Month/Day/Year)
01/29/2013
(Street)

NEW CANAAN, CT 06840
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
_X_ Form filed by One Reporting Person
___ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock               26,766 D  
Common Stock 06/25/2013   C   155,366 A (1) 155,366 I See footnotes (2) (9)
Common Stock 06/25/2013   C   608,670 A (1) 764,036 I See footnotes (2) (9)
Common Stock 06/25/2013   P   533,333 A $ 15 1,297,369 I See footnotes (2) (9)

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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
8% Convertible Promissory Notes (3) 01/29/2013   P   $ 204,724     (3)   (3) Series Four Senior Preferred Stock (3) (3) $ 204,724 I See footnotes (2) (9)
Warrant (right to purchase) $ 0.01 01/29/2013   P   52,736   01/29/2014 01/29/2020 Series One Preferred Stock 52,736 $ 0.01 52,736 I See footnotes (2) (9)
Warrant (right to purchase) $ 0.01 01/29/2013   P   206,003   01/29/2014 01/29/2020 Series Two Preferred Stock 206,003 $ 0.01 206,003 I See footnotes (2) (9)
8% Convertible Promissory Notes (3) 02/15/2013   P   $ 409,448     (3)   (3) Series Four Senior Preferred Stock (3) (3) $ 614,172 I See footnotes (2) (9)
Series Four Senior Preferred Stock (1) 03/07/2013   P   103,819     (1)   (1) Common Stock 103,819 $ 12 103,819 I See footnotes (2) (9)
8% Convertible Promissory Notes (3) 03/07/2013   C     $ 618,569.36   (3)   (3) Series Four Senior Preferred Stock 51,547 (3) 0 I See footnotes (2) (9)
Series Four Senior Preferred Stock (1) 03/07/2013   C   51,547     (1)   (1) Common Stock 51,547 (1) 155,366 I See footnotes (2) (9)
Series One Preferred Stock (4) 03/07/2013   J(4)     110,000   (4)   (4) Common Stock 110,000 (4) 0 I See footnotes (2) (9)
Series One Preferred Stock (4) 03/07/2013   J(4)   394,166     (4)   (4) Series Five Junior Preferred Stock 394,166 (4) 394,166 I See footnotes (2) (9)
Series One Preferred Stock (4) 03/07/2013   J(4)     394,166   (4)   (4) Series Five Junior Preferred Stock 394,166 (4) 0 I See footnotes (2) (9)
Series Five Junior Preferred Stock (1) 03/07/2013   J(4)   394,166     (1)   (1) Common Stock 394,166 (1) 394,166 I See footnotes (2) (9)
Warrant (right to purchase) $ 0.01 03/07/2013   J(4)     52,736 01/29/2014 01/29/2020 Series One Preferred Stock 52,736 (4) 0 I See footnotes (5) (9)
Warrant (right to purchase) $ 0.0028 03/07/2013   J(4)   188,970   01/29/2014 01/29/2020 Series Five Junior Preferred Stock 188,970 $ 0.0028 188,970 I See footnotes (5) (9)
Warrant (right to purchase) $ 0.0028 03/07/2013   S(5)     44 01/29/2014 01/29/2020 Series Five Junior Preferred Stock 44 $ 0.0028 188,926 I See footnotes (5) (9)
Warrant (right to purchase) $ 0.0028 03/07/2013   C     188,926 01/29/2014 01/29/2020 Series Five Junior Preferred Stock 188,926 $ 0.0028 0 I See footnotes (5) (9)
Series Five Junior Preferred Stock (1) 03/07/2013   C   188,926     (1)   (1) Common Stock 188,926 (1) 583,092 I See footnotes (5) (9)
Warrant (right to purchase) $ 0.01 03/07/2013   J(6)     206,003 01/29/2014 01/29/2020 Series Two Preferred Stock 206,003 (6) 0 I See footnotes (7) (9)
Warrant (right to purchase) $ 0.08 03/07/2013   J(6)   25,750   01/29/2014 01/29/2020 Series Five Junior Preferred Stock 25,570 $ 0.08 25,750 I See footnotes (7) (9)
Warrant (right to purchase) $ 0.08 03/07/2013   S(7)     172 01/29/2014 01/29/2020 Series Five Junior Preferred Stock 172 $ 0.08 25,578 I See footnotes (7) (9)
Warrant (right to purchase) $ 0.08 03/07/2013   C     25,578 01/29/2014 01/29/2020 Series Five Junior Preferred Stock 25,578 $ 0.08 0 I See footnotes (7) (9)
Series Five Junior Preferred Stock (1) 03/07/2013   C   25,578     (1)   (1) Common Stock 25,578 (1) 608,670 I See footnotes (7) (9)
Series Four Senior Preferred Stock (1) 06/25/2013   C     155,366   (1)   (1) Common Stock 155,366 (1) 0 I See footnotes (2) (9)
Series Five Junior Preferred Stock (1) 06/25/2013   C     608,670   (1)   (1) Common Stock 608,670 (1) 0 I See footnotes (2) (9)
Stock Option (right to buy) $ 10.85 05/15/2013   P     60,000   (8) 05/15/2023 Common Stock 60,000 $ 10.85 60,000 D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
SCHMERTZLER MICHAEL
1300 VALLEY ROAD
NEW CANAAN, CT 06840
  X   X    

Signatures

 /s/ Mark E. Boulding, attorney-in-Fact   06/27/2013
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) Each share of Series Four Senior Preferred Stock and each share of Senior Five Junior Preferred Stock converted automatically into one share of Common Stock upon the closing of PTC Therapeutics, Inc.'s initial public offering without payment of further consideration. The Series Four Senior Preferred Stock and the Series Five Junior Preferred Stock had no expiration date.
(2) Securities held by Section Six Partners, L.P.
(3) The convertible promissory notes issued as part of PTC Therapeutics, Inc.'s bridge financing in January and February 2013 were (1) payable upon demand of the holders at any time on or after the first anniversary of the date of issuance and (2) convertible into shares of the same class and series of capital stock of PTC Therapeutics, Inc. issued to other investors in the next qualified financing (with gross proceeds of at least $20 million) at a conversion price equal to the price per share paid by other investors in such financing.
(4) In connection with a recapitalization and reverse stock split that occurred on March 7, 2013, each share of Series One Preferred Stock converted automatically into a number of shares of Series Five Junior Preferred Stock equal to a fraction, the numerator of which was 430 and the denominator of which was 120, without payment of further consideration. Warrants to purchase shares of Series One Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio. The Series One Preferred Stock had no expiration date.
(5) On March 7, 2013, the warrants to purchase shares of Series One Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio, and were automatically exercised for shares of Series Five Junior Preferred Stock without further action by the holders thereof at the as-adjusted exercise price of $12 a share. The exercise price was paid on a cashless basis, resulting in PTC Therapeutics, Inc. withholding 44 of the reporting person's warrant shares to pay the exercise price and issuing to the reporting person the remaining 188,926 shares of Series Five Junior Preferred Stock. PTC Therapeutics, Inc. also paid $8.64 to the reporting person in lieu of fractional shares. The warrant shares are held by Section Six Partners, L.P.
(6) In connection with a recapitalization and reverse stock split that occurred on March 7, 2013, each share of Series Two Preferred Stock converted automatically into a number of shares of Series Five Junior Preferred Stock equal to a fraction, the numerator of which was 15 and the denominator of which was 120, without payment of further consideration. Warrants to purchase shares of Series Two Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio. The Series Two Preferred Stock had no expiration date.
(7) On March 7, 2013, the warrants to purchase shares of Series Two Preferred Stock were automatically adjusted to be exercisable into shares of Series Five Junior Preferred Stock at the applicable conversion ratio, and were automatically exercised for shares of Series Five Junior Preferred Stock without further action by the holders thereof at the as-adjusted exercise price of $12 a share. The exercise price was paid on a cashless basis, resulting in PTC Therapeutics, Inc. withholding 172 of the reporting person's warrant shares to pay the exercise price and issuing to the reporting person the remaining 25,578 shares of Series Five Junior Preferred Stock. PTC Therapeutics, Inc. also paid $8.47 to the reporting person in lieu of fractional shares. The warrant shares are held by Section Six Partners, L.P.
(8) This option was granted on May 15, 2013 and vests over three years, with 8.33% of the shares underlying the option vesting on August 15, 2013 and an additional 8.33% of the original number of shares underlying the option vesting at the end of each successive three-month period thereafter.
(9) Mr. Schmertzler is a general and limited partner of, and trustee of certain family trusts holding interests in, Section Six Partners, L.P. Mr. Schmertzler disclaims beneficial ownership of the shares held by Section Six Partners, L.P. except to the extent of any pecuniary interest therein.
 
Remarks:
This Form 4 is being filed in two parts, of which this is the first of two.

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