Figure 6. Schematic representation of the MERTK gene at the transcript level and functional domains of the MerTK protein. The MERTK gene consists of 19 exons. Mutations in the MERTK gene are distributed along the entire gene. MerTK is a 999 amino acid protein that contains several conserved domains: Ig-like C2-type 1 (IgL1), Ig-like C2-type 2 (IgL2), fibronectin type-III 1 (FB1), fibronectin type-III 2 (FB2), transmembrane (TM), and protein kinase (PK). Numbers under the protein line indicate the boundaries of each domain. Nucleotide 1 is A of the ATG initiation codon according to RefSeq NM_006343.2. The amino acid residues are numbered according to RefSeq NP_006334.2, starting at the initiator methionine residue.