Sec Form 4 Filing - NBGE Manager, LLC @ Proto Labs Inc - 2012-11-21

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 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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1. Name and Address of Reporting Person NBGE Manager, LLC 2. Issuer Name and Ticker or Trading Symbol Proto Labs Inc [ PRLB] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director X __ 10% Owner _____ Officer (give title below) _____ Other (specify below) (Last) (First) (Middle) C/O NORTH BRIDGE GROWTH EQUITY, 950 WINTER STREET, SUITE 4600 3. Date of Earliest Transaction (MM/DD/YY) 11/21/2012 (Street) WALTHAM, MA02454 4. If Amendment, Date Original Filed (MM/DD/YY) 6. Individual or Joint/Group Filing (Check Applicable Line) _____ Form filed by One Reporting Person __ X __ 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 (MM/DD/YY) 2A. Deemed Execution Date, if any (MM/DD/YY) 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 11/21/2012 S 1,417,500 D $ 31 3,404,290 I By North Bridge Growth Equity I, L.P. ( 1 ) Common Stock 1,126 D ( 2 ) Common Stock 610 D ( 3 ) Common Stock 585 I By Angel 2011 Dynasty Trust ( 4 )

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 (MM/DD/YY) 3A. Deemed Execution Date, if any (MM/DD/YY) 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 (MM/DD/YY) 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

Reporting Owners Reporting Owner Name / Address Relationships Director 10% Owner Officer Other NBGE Manager, LLC C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA02454 X ANDERSON EDWARD T C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA02454 X DAMORE RICHARD A C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA02454 X NBGE GP, LLC C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA02454 X NORTH BRIDGE GROWTH EQUITY I LP C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA02454 X North Bridge Growth Management, L.P. C/O NORTH BRIDGE GROWTH EQUITY 950 WINTER STREET, SUITE 4600 WALTHAM, MA02454 X Signatures /s/ Julie M. Regnier, Attorney-in-Fact for NBGE Manager, LLC 11/21/2012 Signature of Reporting Person Date /s/ Julie M. Regnier, Attorney-in-Fact for Edward Anderson 11/21/2012 Signature of Reporting Person Date /s/ Julie M. Regnier, Attorney-in-Fact for Richard D'Amore 11/21/2012 Signature of Reporting Person Date /s/ Julie M. Regnier, Attorney-in-Fact for NBGE GP, LLC 11/21/2012 Signature of Reporting Person Date /s/ Julie M. Regnier, Attorney-in-Fact for North Bridge Growth Equity I, L.P. 11/21/2012 Signature of Reporting Person Date /s/ Julie M. Regnier, Attorney-in-Fact for North Bridge Growth Management, L.P. 11/21/2012 Signature of Reporting Person Date

Explanation of Responses:

( 1 )Represents shares held directly by North Bridge Growth Equity I, L.P. NBGE Manager, LLC ("NBGE") is the managing manager of NBGE GP, LLC, which is the sole general partner of North Bridge Growth Management, L.P., which is the sole general partner of North Bridge Growth Equity I, L.P. NBGE has sole vesting and dispositive power over such shares. Shared voting and investment power over such shares is vested in the managers of NBGE, Edward Anderson and Richard D'Amore. Mr. Anderson and Mr. D'Amore each disclaim any beneficial ownership of such shares, except to the extent of any pecuniary interest therein. This report shall not be deemed an admission that any of the reporting persons is the beneficial owner of such securities for purposes of Section 16 or for any other purpose. ( 2 )Represents shares held of record by Mr. Anderson. ( 3 )Represents shares held of record by Mr. D'Amore. ( 4 )Represents shares held of record by a trust for the benefit of certain of Mr. Anderson's immediate family members. Mr. Anderson's immediate family member is the trustee of the trust. Mr. Anderson disclaims beneficial ownership of these shares, and the filing of this report is not an admission that Mr. Anderson is the beneficial owner of these securities for purposes of Section 16 or any other purpose.

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 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).

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