SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* Novartis Bioventures Ltd (Last) (First) (Middle) 131 FRONT STREET (Street) HAMILTON D0 HM12 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol PROTEOSTASIS THERAPEUTICS, INC. [ PTI ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)
	3. Date of Earliest Transaction (Month/Day/Year) 02/17/2016
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) Form filed by One Reporting Person X Form filed by More than One Reporting Person

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	02/17/2016		C		1,498,791(1)	A	(1)	1,498,791	D(2)
Common Stock	02/17/2016		P		375,000(3)	A	$8	1,873,791	D(2)

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 Securities Underlying Derivative Security (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: 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
Series A Convertible Redeemable Preferred Stock	(4)	02/17/2016		C			10,000,000	(4)	(4)	Common Stock	1,318,932(5)	$0.00	0	D(2)
Series B Convertible Redeemable Preferred Stock	(4)	02/17/2016		C			1,944,315	(4)	(4)	Common Stock	179,859	$0.00	0	D(2)

1. Name and Address of Reporting Person* Novartis Bioventures Ltd (Last) (First) (Middle) 131 FRONT STREET (Street) HAMILTON D0 HM12 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

1. Name and Address of Reporting Person* NOVARTIS AG (Last) (First) (Middle) LICHTSTRASSE 35 (Street) BASEL V8 4056 (City) (State) (Zip) Relationship of Reporting Person(s) to Issuer Director X 10% Owner Officer (give title below) Other (specify below)

Explanation of Responses:

1. This transaction represents the total number of shares of Common Stock of the Issuer (the "Issuer Common Stock") received upon the conversion of the Issuer's Series A Convertible Redeemable Preferred Stock (the "Series A Shares"), the payment of accrued dividends on the Series A Shares and the conversion of the Issuer's Series B Convertible Redeemable Preferred Stock (the "Series B Shares", collectively, the "Preferred Shares").

2. These securities are held directly by Novartis Bioventures Ltd. ("Novartis Bioventures"). Novartis Bioventures is a corporation organized under the laws of Bermuda and is an indirect wholly-owned subsidiary of Novartis AG. Novartis AG is a corporation organized under the laws of Switzerland and is the publicly owned parent of Novartis Bioventures Ltd.

3. These securities were purchased in connection with the initial public offering of the Issuer.

4. The Preferred Shares automatically converted into Issuer Common Stock on a 10.8102-to-1 basis upon the closing of the initial public offering of the Issuer without payment or further consideration. The Preferred Shares were convertible at any time at the election of the Reporting Person and had no expiration date.

5. These securities include shares of Issuer Common Stock received as payment for accrued dividends on the Series A Shares.

Remarks:

	NOVARTIS BIOVENTURES LTD., /s/ Simon Zivi, Chairman	02/17/2016
	NOVARTIS BIOVENTURES LTD., /s/ Laurieann Chaikowsky, Authorized Signatory	02/17/2016
	NOVARTIS AG, /s/ Simon Zivi, Authorized Signatory	02/17/2016
	NOVARTIS AG, /s/ Laurieann Chaikowsky, Authorized Signatory	02/17/2016
	** Signature of Reporting Person	Date
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