Primary structure of MagT1
MagT1 cDNA comprises 2241-base pairs (bp) with an open reading frame of 1005 bp that predicts a protein of 335 amino acids with a relative molecular mass of 38,036 Da (Fig. 1). Hydropathy profile analysis suggested that MagT1 is an integral membrane protein containing five hydrophobic transmembrane-spanning (TM) α helical regions, the first of which is likely cleaved to form the final product with four TM domains (Fig. 1). MagT1 contains a N-linked glycosylation site at residue 215 located in the first extracellular loop. The N-terminal region of MagT1 contains four putative cAMP-dependent protein kinase phosphorylation sites at residues S73, S108, T153 and S162 and four possible protein kinase C phosphorylation sites at residues S38, T48, S103, T111. The short C-terminal cytoplasmic region does not possess any cAMP-dependent or protein kinase C phosphorylation sites. The presence of putative phosphorylation sites for protein kinase A and protein kinase C in the cytoplasmic domain suggests that transport might be regulated by phosphorylation.
Figure 1  Primary amino acid sequence of human hMagT1. Human MagT1 was aligned with human candidate tumor suppressor sequence, N33, and the human implantation associated protein, designated IAP. The six predicted transmembrane domains are overlined and numbered. The amino acid numbers corresponding to the MagT1 protein are shown on the left side.

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