Method For Detecting And Purifying Pancreatic Beta Cells

An isolated nucleic acid that encodes an amino acid sequence of an extracellular domain of Betacam, wherein the amino acid sequence consists essentially of SEQ ID NO:

• 14, SEQ ID NO:
• 15, an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 14 or an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 15.

An isolated polypeptide that consists essentially of SEQ ID NO:

• 14, SEQ ID NO:
• 15, an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 14 or an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 15.

A method of detecting beta cells in a mixture of pancreatic cells comprising detecting the presence of a polypeptide on the surface of the cells, wherein the polypeptide comprises SEQ ID NO:

• 14, SEQ ID NO:
• 15, an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 14 or an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 15, and detection of expression of the polypeptide on the surface of the cells indicates that the cells are pancreatic beta cells.

A method of detecting pancreatic beta cells in an individual in need thereof, comprising administering to the individual an agent that detects the presence of a polypeptide on the surface of the pancreatic beta cells, wherein the polypeptide comprises SEQ ID NO:

• 14, SEQ ID NO:
• 15, an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 14 or an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 15.

A method of isolating pancreatic beta cells from a mixture of pancreatic cells comprising:

• a) contacting the mixture with a reagent that specifically binds to a polypeptide present on the surface of pancreatic beta cells, wherein the polypeptide comprises SEQ ID NO:
• 14, SEQ ID NO:
• 15, an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 14 or an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 15, thereby producing a combination;
• b) maintaining the combination under conditions in which the reagent binds to the polypeptide present on the surface of the pancreatic beta cells, thereby producing a complex of pancreatic beta cells bound to the reagent;
• and
• c) separating the complex from the combination,
• thereby isolating pancreatic beta cells from the mixture of pancreatic cells.

A method of identifying an agent that modulates the biological activity of betacam comprising:

• a) contacting a composition comprising a polypeptide, wherein the polypeptide has an amino acid sequence comprising SEQ ID NO:
• 14, SEQ ID NO:
• 15, an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 14 or an amino acid sequence that has at least 50% identity to SEQ ID NO:
• 15 with an agent to be assessed;
• b) measuring the biological activity of the polypeptide in the presence of the agent compared to a suitable control,
• wherein if the polypeptide modulates the activity of the polypeptide in the presence of the agent compared to the control, then the agent modulates the biological activity of betacam.