SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person* Novartis Bioventures Ltd (Last) (First) (Middle) 131 FRONT STREET (Street) HAMILTON D0 HM12 (City) (State) (Zip)	2. Date of Event Requiring Statement (Month/Day/Year) 02/10/2016	3. Issuer Name and Ticker or Trading Symbol PROTEOSTASIS THERAPEUTICS, INC. [ PTI ]
		4. Relationship of Reporting Person(s) to Issuer (Check all applicable) Director X 10% Owner Officer (give title below) Other (specify below)	5. 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 Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series A Convertible Redeemable Preferred Stock	(1)	(1)	Common Stock	1,318,932(1)	(1)	D(2)
Series B Convertible Redeemable Preferred Stock	(3)	(3)	Common Stock	179,859(3)	(3)	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) CH-4056 BASEL V8 (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. The Series A Convertible Redeemable Preferred Stock (the "Series A Shares") are convertible on a 10.8102-to-1 basis into the Issuer's Common Stock at any time at the election of the Reporting Person and will automatically convert, together with the accrued but unpaid dividends, upon the closing of the Issuer's initial public offering into the number of shares of the Issuer's Common Stock shown in column 3. The Series A Shares do not have an expiration date.

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. The Series B Convertible Redeemable Preferred Stock (the "Series B Shares") are convertible on a 10.8102-to-1 basis into the number of shares of the Issuer's Common Stock as shown in column 3 at any time at the election of the Reporting Person and will automatically convert upon the closing of the Issuer's initial public offering. The Series B Shares do not have an expiration date.

Remarks:

	/s/ Simon Zivi, Chairman	02/10/2016
	/s/ Laurieann Chaikowsky, Authorized Signatory	02/10/2016
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (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).
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