Molecular cloning of PARP (proline/arginine-rich protein) from human cartilage and subsequent demonstration that PARP is a fragment of the NH2-terminal domain of the collagen alpha 2(XI) chain.

We report the molecular cloning of a proline/arginine-rich protein (called PARP) from human cartilage using the polymerase chain reaction (PCR) and degenerate oligonucleotides based on the previously published amino acid sequence of bovine PARP [1]. Subsequently, a reverse transcription-polymerase chain reaction (RT-PCR) was performed with poly(A)-rich RNA from human cartilage using a sense oligonucleotide derived from PARP and an anti-sense oligonucleotide derived from the known sequence of the human collagen alpha 2(XI) chain [2]. Nucleotide sequencing of the PCR product demonstrated that PARP is a fragment of the NH2-terminal non-collagenous (NC3) domain of the collagen alpha 2(XI) chain.