Primary structure of human transferrin receptor deduced from the mRNA sequence

Area of Science:

• Molecular Biology
• Biochemistry
• Cell Biology

Background:

• Vertebrates utilize the carrier protein transferrin for iron uptake.
• Transferrin binds to its receptor, initiating receptor-ligand complex internalization via coated pits.
• The transferrin receptor is a transmembrane glycoprotein with a molecular weight of 180,000, composed of two disulfide-bonded subunits.

Purpose of the Study:

• To determine the nucleotide sequence of the human transferrin receptor mRNA's coding region.
• To deduce the amino acid sequence of the human transferrin receptor protein.

Main Methods:

• Nucleotide sequencing of human transferrin receptor mRNA.
• Deduction of amino acid sequence from mRNA sequence data.

Main Results:

• The human transferrin receptor mRNA coding sequence was determined.
• The amino acid sequence of the transferrin receptor protein was deduced.
• The receptor lacks an N-terminal signal peptide and possesses a membrane-spanning segment 62 amino acids from the N-terminus.

Conclusions:

• The transferrin receptor has an unusual configuration with a small N-terminal cytoplasmic domain.
• The receptor features a large C-terminal extracellular domain of 672 amino acids.