I was really hoping that William Roper would chime in with the answer!
Where MERS is involved as Beneficiary for Lender and Lender’s Successors and Assigns has only been within the last decade.
At the origination of the loan, when the Security Instrument is signed there is attachment of the lien to the Note and temporary perfection, at least under Texas law. The Security Instrument is then filed of record which provides constructive notice to the world that a lien exists. Each needs to verify with their own state laws lien perfection requirements. The filing for perfection would also provide time notice to resolve competing claims to title (Race). To avoid delays in creating securitized trust, MERS is filed of Record as Beneficiary as Nominee for the Originating Lender. (Whether this is legal or not is going to be left up to the courts and is not a relevant point at this time.)
To get to your answer:
As the banks theory goes, the bank would only need to file of record for perfection the Original Security Instrument noting MERS is Nominee (agent) for the Original Lender. (MOM Loan, MERS Originated Mortgage).
From your statement, it appears that this loan was originated as a NON-MOM loan by some type of loan originator. To forward the mortgage upward to securitization the loan originator under real property laws assigned the title to MERS as Nominee to memorialize a negotiation of the Note to a subsequent(s) purchaser(s) of the Note.
The securitized trust (Certificates) and perfection of the securitized trust’s security fall under the Uniform commercial Code Article 9 or Revised Article 9. Assigning the trust’s security does not require filing of record. The trust’s security is the right to collect the payments made under the mortgage as a “Payment(s) Intangible.”
As the Mortgage Note was negotiated, an assignment of the Mortgage Note’s security required filing an assignment of record naming MERS as Nominee for Lender and Lender’s Successors and Assigns in a timely manner to memorialize the negotiation, (2 years later, hmmm.)
What is of interest, the Payment Intangible’s Assignment filed with the securitized trust pre-dated the actual filing of the assignment to MERS!!!
25 word elevator version, public records required an assignment to perfect in MERS name as nominee for real property and the unrecorded securitized trust assignment was not required to be filed for personal property.
As normal, I do not give legal advice on how to use the information and highly recommend you find a damn good real estate/securities attorney. Not an attorney nor do I care to be. God Speed