Multiple Forms of Mouse PG-M, a Large Chondroitin Sulfate Proteoglycan Generated by Alternative Splicing

doi:10.1074/jbc.270.2.958

Multiple Forms of Mouse PG-M, a Large Chondroitin Sulfate Proteoglycan Generated by Alternative Splicing (*)

From the Institute for Molecular Science of Medicine, Aichi Medical University, Nagakute, Aichi 480-11, Japan

↵^§ Present address: Dept. of Orthopedic Surgery, Sapporo Medical University, S1-W16, Chuo-ku, Sapporo 060, Japan.

^¶ To whom all correspondence should be addressed. Tel.: 81-52-264-4811; Fax: 81-56-163-3532.

Abstract

We have isolated and sequenced cDNA clones that encode the core protein of PG-M-like proteoglycan produced by cultured mouse aortic endothelial cells (Morita, H., Takeuchi, T., Suzuki, S., Maeda, K., Yamada, K., Eguchi, G., and Kimata, K.(1990) Biochem. J. 265, 61-68). A homology search of the cDNA sequence has suggested that the core protein is a mouse equivalent of chick PG-M(V1), one of the alternatively spliced forms of the PG-M core protein, which may correspond to human versican. Northern blot analysis revealed three mRNA species of 10, 9, and 8 kilobases (kb) in size. The analysis of PG-M mRNA species in embryonic limb buds and adult brain revealed the presence of other mRNA species with different sizes; the one with the largest size (12 kb) was found in embryonic limb buds, and the ones with smaller sizes of 7.5 and 6.5 kb were in adult brain. Sequencing of cDNA clones for the smaller forms in the adult brain showed that they were different from PG-M(V1) in encoding the second chondroitin sulfate attachment domain (CS α) alone. Occurrence of the PCR products striding over the junction of the first and second chondroitin sulfate attachment domains suggested that a mRNA of 12 kb in size corresponded to a transcript without the alternative splicing (PG-M(V0)). It is likely, therefore, that multiforms of the PG-M core protein may be generated by alternative usage of either or both of the two different chondroitin sulfate attachment domains (α and β) and that molecular forms of PG-M may vary from tissue to tissue by such an alternative splicing.

Footnotes

↵* This work was supported in part by special coordination funds of the Science and Technology Agency of the Japanese Government; a grant-in-aid from the Ministry of Education, Culture, and Science of the Japanese Government; and a special research fund from Seikagaku Corporation. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore by hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

The nucleotide sequence(s) reported in this paper has been submitted to the GenBank™/EMBL Data Bank with accession number(s) D16263 [GenBank]and D28599[GenBank].
↵¹ The abbreviations used are:

EGF

epidermal growth factor

PCR

polymerase chain reaction

kb

kilobase pairs

bp

base pairs.
↵²M. Ujita, T. Shinomura, and K. Kimata, submitted for publication.
↵³T. Shinomura, K. Ito, M. Zako, M. Ujita, and K. Kimata, unpublished observation.
- Received June 21, 1994.