Masp2 (rat, Q9JJS8) - manual literature synthesis

No deep-research API was available; this synthesis was assembled by hand from cached
publications in publications/ and the UniProt record.

Identity and gene structure

• Rat MASP-2 (mannan-binding lectin serine protease 2), 685 aa precursor; single gene also
  encodes MAp19 (isoform 2) by alternative polyadenylation/splicing
  PMID:10586086.
• Domain order CUB1-EGF-CUB2-CCP1-CCP2-SP PMID:22167201.
• Hepatic biosynthesis, plasma protein PMID:10586086.

Molecular function

• Serine protease that cleaves C4 and C2 PMID:15060079;
  rat zymogen and activated forms produced recombinantly; MBP stimulates autoactivation
  PMID:15060079.
• Active-site Ser613 (mature numbering; Ser632 in the precursor) and activation-cleavage
  Arg424 (mature; Arg443 precursor) PMID:20118239.
• Wild-type rat MASP-2 autoactivates PMID:20118239.
• Accessory (exosite) binding of C4, and of C4b after cleavage PMID:15060079;
  PMID:17204478.

Assembly

• Ca2+-independent homodimer via CUB1-EGF; Ca2+-dependent binding to MBL collagenous region
  PMID:10913141;
  PMID:10913141.
• MBL binding site in collagen-like domain PMID:14724269.
• Crystal structure of rat CUB1-EGF-CUB2 dimer PMID:12743029.
• Part of rat MBL activation complex PMID:10586086.

Process

• Lectin-pathway initiation: MBL/ficolins bind pathogen carbohydrates, activating MASP-2
  PMID:20118239;
  activation only on carbohydrate target PMID:20118239.
• C4b covalently deposits on pathogen surface PMID:17204478.

Not supported for rat / likely over-annotation

• Golgi apparatus (secretory transit only), cell-surface PRR signaling (MBL/MASP is a soluble
  pattern-recognition complex, not a cell-surface receptor).