Initial Statement of Beneficial Ownership (3)

FORM 3	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES	OMB APPROVAL OMB Number: 3235-0104 Estimated average burden hours per response... 0.5
	Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940

1. Name and Address of Reporting Person ^*

Zago Wagner M.

2. Date of Event Requiring Statement (MM/DD/YYYY) 6/9/2017

3. Issuer Name and Ticker or Trading Symbol

Prothena Corp plc [PRTA]

(Last) (First) (Middle)

C/O PROTHENA BIOSCIENCES INC, 331 OYSTER POINT BOULEVARD

4. Relationship of Reporting Person(s) to Issuer (Check all applicable)

_____ Director _____ 10% Owner
___ X ___ Officer (give title below) _____ Other (specify below)
Chief Scientific Officer /

(Street)

SOUTH SAN FRANCISCO, CA 94080

(City) (State) (Zip)

5. If Amendment, Date Original Filed (MM/DD/YYYY)

6. Individual or Joint/Group Filing (Check Applicable Line)

_ X _ Form filed by One Reporting Person
___ 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 Derivate Security (Instr. 4)	2. Date Exercisable and Expiration Date (MM/DD/YYYY)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form of Derivative Security: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivate Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security		6. Nature of Indirect Beneficial Ownership (Instr. 5)
Stock Option (right to buy)	⁽¹⁾	1/29/2023	Common Stock	16000	$6.41	D
Stock Option (right to buy)	⁽²⁾	9/3/2023	Common Stock	15000	$20.17	D
Stock Option (right to buy)	⁽³⁾	2/4/2024	Common Stock	15000	$29.81	D
Stock Option (right to buy)	⁽⁴⁾	3/11/2025	Common Stock	19000	$27.81	D
Stock Option (right to buy)	⁽⁵⁾	2/24/2026	Common Stock	21000	$34.61	D
Stock Option (right to buy)	⁽⁶⁾	2/22/2027	Common Stock	20000	$55.00	D

Explanation of Responses:
(1)	The original grant was for 36,000 shares, of which 20,000 shares have been exercised and sold. The remaining shares underlying the option (16, 000 shares) are fully vested and exercisable as of the date hereof.
(2)	A portion of the shares (14,062 shares) underlying this option are vested and exercisable as of the date hereof. The remaining shares subject to the option (938 shares) vest in successive, equal monthly installments through September 3, 2017, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.
(3)	A portion of the shares (12,500 shares) underlying this option are vested and exercisable as of the date hereof. The remaining shares subject to the option (2,500 shares) vest in successive, equal monthly installments through February 4, 2018, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.
(4)	A portion of the shares (10,291 shares) underlying this option are vested and exercisable as of the date hereof. The remaining shares subject to the option (8,709 shares) vest in successive, equal monthly installments through March 11, 2019, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.
(5)	A portion of the shares (6,562 shares) underlying this option are vested and exercisable as of the date hereof. The remaining shares subject to the option (14,438 shares) vest in successive, equal monthly installments through February 24, 2020, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.
(6)	The shares subject to the option will vest and become exercisable as to 25% of the total number of shares subject to the option on February 22, 2018 and with respect to 1/48th of the total number of shares subject to the option in successive, equal monthly installments on each monthly anniversary thereafter, subject to the Reporting Person's continued employment with the Issuer on each such vesting date.

Reporting Owners
Reporting Owner Name / Address	Relationships
Reporting Owner Name / Address	Director	10% Owner	Officer	Other
Zago Wagner M. C/O PROTHENA BIOSCIENCES INC 331 OYSTER POINT BOULEVARD SOUTH SAN FRANCISCO, CA 94080			Chief Scientific Officer

Signatures
/s/ A.W. Homan, as Attorney-in-Fact for Wagner M. Zago		6/13/2017
^** 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).
Note:	File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.