Disease relevance of Ptprn

• A novel protein [designated protein tyrosine phosphatase-like protein (PTPLP)] which is distantly related to receptor-type protein tyrosine phosphatases (PTPases) was cloned from a rat pheochromocytoma cell line [1].
• It is closely related to the diabetic autoantigen ICA512 (IA-2) (42% identity overall; 80% in the 260-amino acid PTP domain) and thus a potential target of autoimmunity in diabetes mellitus [2].

High impact information on Ptprn

• Among the cDNA products that reacted with the IDDM serum, we identified one cDNA clone whose open reading frame encodes a protein with a predicted mass of 105 kDa that we termed "ICA105" for 105-kDa islet cell antibody [3].
• The 40-kDa antigen has recently been identified as the tyrosine phosphatase-like protein IA-2 (ICA512) whereas the 37-kDa antigen has been suggested to be a different protein that has structural similarity to IA-2 [4].
• The highest differences in the magnitude of proliferative responses were seen for ICA512, followed by membrane preparations of RIN cells, GAD65, and human pancreas [5].
• Treatment of rat pituitary GH4C1 cells with estradiol, insulin, and epidermal growth factor induces secretory granule accumulation, PRL storage, and stabilization of ICA512, a membrane protein associated with secretory granules [6].
• Accumulation of ICA512 resembles that of prolactin storage, for the combination of all three, estradiol, insulin, and epidermal growth factor, gave the greatest induction, which was maximal at 4 days [7].

Anatomical context of Ptprn

• Overexpression of the PTPLP decreased the basal PTPase activity of COS-7 cells for Raytide [1].
• These results indicate that the enlargement of the secretory granule compartment results in the stabilization of ICA512 and raise the possibility that trafficking of secretory granules may affect ICA512's function and vice versa [7].
• The same triple treatment induced more than 6-fold accumulation of both the precursor (100 kDa, pro-ICA512) and the mature forms (60-70 kDa, ICA512 transmembrane fragment) of ICA512, a receptor protein tyrosine phosphatase-like protein that is preferentially localized in secretory granule membranes [7].

Associations of Ptprn with chemical compounds

• Stabilization of the receptor protein tyrosine phosphatase-like protein ICA512 in GH4C1 cells upon treatment with estradiol, insulin, and epidermal growth factor [7].

References