The genes COL4A5 and COL4A6, coding for basement membrane collagen chains α5(IV) and α6(IV), are located head-to-head in close proximity on human chromosome Xq22 and COL4A6 is transcribed from two alternative promoters

M. Sugimoto, T. Oohashi, Y. Ninomiya

Research output: Contribution to journalArticle

74 Citations (Scopus)

Abstract

The genes for the α5(IV) and α6(IV) chains of human basement membrane collagen type IV have been found together on chromosome X at segment q22 and have been reported to be arranged in a head-to-head fashion. Here we report the 5' flanking sequences of COL4A5 and COL4A6 and that COL4A6 is transcribed from two alternative promoters in a tissue-specific fashion. Analysis of the sequence immediately upstream of the transcription start sites revealed some features of housekeeping genes-i.e., the lack of a TATA motif and the presence of CCAAT and CTC boxes. Further analysis revealed that COL4A6 contains two alternative promoters that control the generation of two different transcripts. One transcription start site (from exon 1') is 442 bp away from the transcription start site of COL4A5, while an alternative transcription start site (from exon 1) is located 1050 bp from the first one and drives the expression of a second transcript that encodes an α 6(IV) chain with a different signal peptide. Reverse transcription-PCR experiments revealed that the transcript from exon 1' is abundant in placenta, whereas the transcript from exon 1 is more frequently found in kidney and lung. These results provide additional clues to answering the general question of what mechanisms are used to generate unique basement membrane structures in different tissues.

Original languageEnglish
Pages (from-to)11679-11683
Number of pages5
JournalProceedings of the National Academy of Sciences of the United States of America
Volume91
Issue number24
DOIs
Publication statusPublished - Dec 6 1994

Keywords

  • alternative promoter
  • bidirectional promoter
  • collagen IV
  • extracellular matrix
  • synteny

ASJC Scopus subject areas

  • General

Fingerprint Dive into the research topics of 'The genes COL4A5 and COL4A6, coding for basement membrane collagen chains α5(IV) and α6(IV), are located head-to-head in close proximity on human chromosome Xq22 and COL4A6 is transcribed from two alternative promoters'. Together they form a unique fingerprint.

  • Cite this