Alternative Splicing of the Unique “PLUS” Domain of Chicken PG-M/Versican Is Developmentally Regulated

doi:10.1074/jbc.272.14.9325

Alternative Splicing of the Unique “PLUS” Domain of Chicken PG-M/Versican Is Developmentally Regulated*

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

^‡ To whom correspondence should be addressed. Tel.: 81-52-264-4811 (ext. 2088); Fax: 81-561-63-3532.

Abstract

We investigated the occurrence of alternatively spliced forms (V0, V1, V2, and V3) of PG-M/versican, a large chondroitin sulfate proteoglycan in developing chicken retinas, using the reverse transcription-polymerase chain reaction. We characterized the PLUS domain, which is apparently unique to the chicken molecule and is regulated by alternative splicing. PG-M in chicken retinas consisted of four forms with (V0, V1, V2, and V3) and two forms without (V1 and V3) the PLUS domain (PG-M⁺ and PG-M⁻, respectively). The four forms of PG-M⁺ were found in all samples examined, but the occurrence of the two PG-M⁻ forms was regulated developmentally. Genomic analysis has revealed that the PLUS and CS-α domains are encoded by a single exon, and this exon has an internal alternative 5′-splice donor site, allowing alternative spliced forms that do not include the 3′-end of the exon. Sequences corresponding to the chicken PLUS domain (plus) were not found in mouse and human and may have disappeared during evolution. Sequence similarity suggests that the PLUS domain corresponds to the keratan sulfate attachment domain of aggrecan and that it has a distinct function in the chicken eye.

Footnotes

↵* This work was supported in part by special coordination funds from the Science and Technology Agency of the Japanese Government, by a grant-in-aid from the Ministry of Education, Culture, and Science of the Japanese Government, and by a special research fund from Seikagaku Corp. The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
↵¹ The abbreviations used are:

EGF

epidermal growth factor

CRP

complement regulatory protein

CS

chondroitin sulfate

RT-PCR

reverse transcription-polymerase chain reaction

KS

keratan sulfate

bp

base pair(s)
↵² M. Zako, T. Shinomura, O. Miyaishi, M. Iwaki, and K. Kimata, unpublished observations.
- Received May 15, 1996.
- Revision received December 26, 1996.